Pegasus Mail & Mercury

Hi, I'm using Mercury/32 v4.52 with the MercuryI module, but I also experienced this issue with v4.01b.  When I delete a folder in Thunderbird (currently using version 2.0.0.9, but this has happened with every version since 1.5), it is removed from HIERARCH.PM but not from IMAPSUB.PM.  Thus, the folder reappears, but grayed out and ...