The problem appears to be solved. I'm reporting what I did in case it helps others!

A suggestion on another list was to completely clear out all references to the print spooler and installed printers from the Registry. This made use of an application named cleanspl.exe, which is one of the Windows Server 2003 Resource Kit Tools (the complete kit can be downloaded from Microsoft; the individual file is also available from other sites). This seems to have done the job. After running it, I reinstalled my Canon printer driver (which, surprisingly, also reactivated PDFCreator, my PDF driver, as well). This didn't seem to change anything immediately, but on starting up the computer this morning, the problem had disappeared

Let's hope it stays that way!

I'm using Pegasus 4.50 PB1 dated 1 Sep 2008.

Recently - I'm not sure exactly when or why - Pegasus has become very slow when opening messages in folders (I usually keep the message preview window closed). Double-clicking on a message results in a pause of 6.25 seconds before it appears. It doesn't matter whether the folder has one message in it or a thousand, the delay is the same. It also doesn't matter if the folder is directly off the "My mailbox" root or is a sub-folder. However, there is one folder, and one only, for which the delay is a mere 3.5 seconds.

Spamhalter is turned off. I suspected my virus checker (Kaspersky) but turning that off makes no difference. If I enable the preview windows, message texts appear in the message pane immediately I single-click on folders or items in the message list.

Has anyone any idea why double-clicking should suddenly have become so slow, or how to cure it?

[quote user="huntingtower"]

I'm using Pegasus 4.50 PB1 dated 1 Sep 2008.

Recently - I'm not sure exactly when or why - Pegasus has become very slow when opening messages in folders (I usually keep the message preview window closed).[/quote]

Is the (in Pegasus Mail) selected printer accessible (not on a disconnected or slow network, e.g.)?

I had to check this, as I never print messages! The default printer is available, but the dialog box is equally slow to appear and a message to print.

I forgot to mention that I'm running a dual-boot system with XP Sp3 and Windows 7 64-bit. The two versions of Pegasus share the same mailbox and data files. It has only just occurred to me to test the Windows 7 installation. In that version, double-clicking opens messages within a second or so. At the moment, my Windows 7 installation is really only for testing purposes and 90% of the time I'm working still in XP. I wonder if there's some configuration setting made by the Windows 7 installation of Pegasus that causes the XP version of Pegasus to run slow in this respect. Can anybody suggest a possible cause? By the way, I've just upgraded both Pegasus Mail installations to 4.51 of 23 Jun 2009.

Further tests:

- My Windows 7 and XP installations use a common mailbox (on a separate logical drive to either Windows version).

- The Windows 7 version doesn't exhibit the problem but the XP one does.

- While in XP, running the Windows 7 installation of Pegasus causes the problem.

- On uninstalling Pegasus on XP and reinstalling to new mailbox, the problem recurs with default messages.

- Running Pegasus in preview mode allows message to appear instantly in preview pane when selected but double-clicking on a message results in the same delay.

The conclusion must that the problem has nothing to do with Windows 7 but is the result of some interaction between Pegasus and Windows XP, but only when double-clicking a message to open it.

Anyone got any further ideas?

> The conclusion must that the problem has nothing to do with Windows 7 but is the result of some interaction between Pegasus and Windows
> XP, but only when double-clicking a message to open it.

I personally believe this is a WinXP problem but it's not all WinXP systems.  There is something that creates a problem when looking at a network drive mounted on a different Windows server.  In my experience it does not affect the connection to a mailbox on a Netware or Linux server or to a local hard drive.   This started for me months ago with one of the Windows upgrades.

This is not caused by the network, it is caused by WinXP.  The what is the problem and I've not been able to locate the problem.  FWIW, you look around long enough and I suspect that you'll find another application that has a problem opening a file the first time it accesses a network drive on another Windows system.

The drives concerned are all local ones.

My copy of XP has indeed in the past exhibited odd delays that look like the result of some process waiting for a timeout. I was never able to find out what it was and something I did made it go away. The solution probably involves me successively removing processes until the problem goes away, a time-consuming activity that I'd prefer to avoid if possible!

[quote user="huntingtower"]- Running Pegasus in preview mode allows message to appear instantly in preview pane when selected but double-clicking on a message results in the same delay.[/quote]

Strange.

To the geeks: Whats the difference between accessing a message via preview-mode or via window-mode? Index- and message-files are the same... Is preview-mode preloading something, veiling the delay?

The only difference I see is that preview-mode has not to open an extra window. Can that "simple" thing, a new window, cause such a delay?

Progress, of a sort, has been made.

Using msconfig, I've tracked the problem to the XP printer spooler function. Stopping that process clears the fault. So IDW was right to suspect a printer connection. The suriving problem is that I can't discover which process running within the spooler is causing the problem. I've uninstalled all the printers and that doesn't cure it. I've stopped all the processes running within it and that doesn't help either.

Currently, I'm manually stopping and starting the spooler ("net start/stop spooler" from the cmd line)  but that's a crude workround.

If anyone has any ideas of where to go from here, or what further diagnostics to apply, I'd be delighted to learn!

> If anyone has any ideas of where to go from here, or what further diagnostics to apply, I'd be delighted to learn!

As a quick workaround try setting the windows default printer to one of the PDF type printers so that Pegasus Mail will open and read mail without having to look at the network printer.  

If this fixes the problem with Pegasus Mail then I would download the latest printer driver and install it so that the system is talking to the network printer via a LPT port.
This means that the printer is setup so that you can print from an old DOS type program that only prints via the LPT ports.

[quote user="Thomas R. Stephenson"]
As a quick workaround try setting the windows default printer to one of the PDF type printers so that Pegasus Mail will open and read mail without having to look at the network printer.  If this fixes the problem with Pegasus Mail then I would download the latest printer driver and install it so that the system is talking to the network printer via a LPT port. This means that the printer is setup so that you can print from an old DOS type program that only prints via the LPT ports.[/quote]

Setting a PDF printer as default certainly helps, reducing the time delay to about 1 second. Uninstalling all printers and reinstalling just the driver for my main printer (Canon PIXMA ip4600) on LPT1 increases the delay to ten seconds from its previous six!  Uninstalling and reinstalling again with automatic port detection doesn't change this. But installing the PDF printer again (PDFCreator) and setting it as default reduces it to 1 second as before. Seems like the best I'm going to get ...

 Why this problem should suddenly have arisen when I've been using the Canon printer with various versions of Pegasus Mail for about two years baffles me!