Palm Treo 700p Stops Syncing Calendar and Contacts and Switches Sync Type to "Do Nothing"

So I've been using my Palm Treo 700p for quite awhile and never had too many problems with it syncing--and that is a little surprising because I use bluetooth and some other complicated settings.

All of a sudden, I noticed I wasn't seeing my appointments from Outlook in my calendar and my calendar wasn't showing up in Outook. It also affected contacts. I checked and the settings under Hotsync/Custom/Calendar and Contacts where both set to "Do Nothing". I changed them to synchronize, did a sync, and they went back to "Do Nothing". I made sure that I wasn't doing any kind of Exchange sync (that can disable the functionality for syncing to the desktop), but it still wouldn't stay set.

When I went into check some settings for Versamail and for the Verizon sync software, it caused the Treo to reset. I removed them temporarily so that I could continue to figure out what was wrong.

Finally, I did a re-install of my Palm desktop software, set it to sync, then did a re-sync with the handheld and so far it has stuck. I didn't uninstall OR reinstall the conduits--I left them as they were since I didn't have the install CD handy, just the download of the Palm software.

I'm not sure why it stopped, but the palm software re-install fixed it. It may have been that I had turned on Exchange style syncing at some point in testing something for a client and the palm wouldn't let me switch back. The re-install probably fixed some registry settings or something like that.

Updated: It worked for a few more syncs, then went back to blocking appointments and contacts. I had to do a hard reset on the device and create a new user profile. Now it seems to be sticking, after 4 days anyway.