After installing Palm Desktop 4.2.1 on Panther 10.3.4 and running it with absolutely no problems for a week; suddenly, when I went to open the Palm Desktop application ... I got the introductory Palm 'splash screen', and then an 'eternal' spinning beach ball. In other words, the application does not respond and I have to force quit.
(I had recently updated my system with the current Apple security updates through Software Update.)
Note: I can still Hotsync fine. Hotsync Manager opens.
After calling Palm Support, the technician suggested that I try clicking on my "User Data" file in the Users folder ... no luck. Next, we tried opening "User Data Archive" file. It worked. Palm Desktop opened (but I still could not access my user file; ie, my hotsync name). When I click on my user name in Palm Desktop, I get the 'eternal' spinning beach ball yet again.
FYI: I created a new user file (hotsync name) then tried to delete my regular user file and got the message: One or more files associated with this user/profile are currently busy or in use. They can't be deleted now. 
I uninstalled Palm Desktop; then reinstalled it. I hard reset my Palm (contents backed up to expansion card) then restored from backup card. I hotsynced to my Mac. Then started up Palm Desktop. No luck ... same problem.
FYI: Also, I noticed some icon images were corrupted (Palm Users; Set_Backup; sync.ini) sometime during the uninstall and the reinstall of Palm Desktop. (Some had a distorted icon of Apple Preview instead of their original icon. Strange.)
Luckily, I have Chronos Personal Organizer 4.5. It syncs fine (using it's own conduit, which replaces the Date Book, Contact, Memo, and Task conduit of the Palm Desktop app) to work in the interim until I find a solution.
Any ideas what the problem might be?