Thank you so much for sharing this. It did solve my problem: same issue,  was experimenting with dual screen. Using Pegasus 4.51. After updating to 4.63 still same problem.

Editing state.pmj is indeed less drastic as removing it also removed the folderview. (which I did, but luckely had it renamed instead of deleted).

Here's what's up:  for about a week now, pushing the Move button either in a folder window or in the message reader absolutely locks up my program.  However, I can drag a message from one folder to another to move it.  I was using w32-441 and hoped that a reinstall would fix the problem.  Downloaded w32-462 and installed today.  Nothing changed.  Deleted the folder hierarcy HIERARCH.PM file and let it recreate.  No good.

Program acts like it's trying to open a new window (like the choose folder window), so disables all current windows, but the new window never appears.  Can't close it so can't continue working. Only solution is to End Task in the Task Manager.  Working on a dual screen extended desktop.  Never had this problem under the same monitor config.  Spell check and choose folder windows would appear on the other monitor often, instead of on the monitor on which PMail was currently running. [Just tried it on the netbook screen in a single monitor config.  Same problem.  Reboot didn't help either.]

Anyone have some help?

Update:  The thread about Windows 7 and dual screens (Oct. 1, 2011) gave me an idea.  The monitor I am currently using has a lower max. resolution than the usual one.  The choose folder window may be opening off screen due to its last location on the higher resolution monitor.  Think I'll try deleting the STATE.PMJ file and restarting.

Voila!  Problem solved.  The offending window is properly called "Select a mail folder". 

A little further reflection leads me to believe that the problem wasn't screen resolution, but rather monitor placement.  I had the second monitor above the netbook and then moved them side by side adjusting the relationship in Graphic Properties using the Intel Graphics Media Accelerator Driver for Mobile.  Anyone want to write a routine to handle this occurrence?  Wonder if would give the same unsatisfactory result using Windows Display Properties to re-orient the monitors to each other.  Play with it.  Possible that I had a crash with PMail open.  Then switched the display configuration after reboot but before opening PMail, not sure.  Was a long time ago.

Thanks for posting this. Had the identical problem.

A small but possibly useful addition to your solution:

Open STATE.PMJ in an ordinary ascii editor, and look at the value for "Select a mail folder=". Most values are quadruples like 262,362,594,777

I had one that started with a -2354, which made it clear that the multiple monitors I was using had incredibly confused the program.

I edited this one line to a more reasonable value, restarted the program an all was well. It's just a little less drastic that deleting the file.