So I recently started getting the following error when attempting to synchronize my Treo 800w WM6.1 device with my hosted Exchange 2007 provider via Exchange ActiveSync:

Synchronization could not be completed. If this condition persists, try deleting and then re-creating the device's sync relationships. Error Code: 0x80004005

This would only occur when I tried to synchronize email, but sync'ing contacts, calendar, and tasks still seemed to work fine.

After a bunch of trial and error, I finally discovered the reason was that my pim.vol file was corrupted (I discovered this when I tried to do a Sprite backup of my entire device and it was failing and after examining the log it showed it was failing on the pim.vol file). I renamed the pim.vol file, did a soft reset to allow the device to re-create a new pim.vol file, and then attempted to re-create my Exchange activesync partnership and voila, it worked now!

My question is - what exactly is stored in the pim.vol file? I have hannip's poutlook sms hack installed so I'm not using the palm sms app, but it appears that sms messages are stored in my cemail.vol file. I'm assuming that the pim.vol file holds emails, calendar, contacts, and tasks, but is this correct? Is there more that the file holds?
(I used to know this, but haven't really played around much with the device in a while and so my memory is definitely fuzzy)