I've seen all kinds of fun error messages, such as the 'OLERR: (number)' errors in HotSync. Palm's troubleshooting guide suggests they've just thrown up their hands.
I went through too many twists and turns to remember, but I finaly defeated a wide range of Outlook and Palm misbehaviors.
At work with Beyond Contacts I think the fix was repairing some bad Outlook PST files and running "outlook /resetfolders" (see also this list of Outlook command line switches), but I also got this advice from tech support:
I am writing in response to your email regarding Beyond Contacts. Please try the following steps to correct the problem. Before completing these steps, please confirm that all of your data is up to date in MS Outlook on your computer.At home I decide to upgrade Outlook 2000 to 2003. I realized it was very unlikely that he current conduits were really aimed at Outlook 3 versions old. I then removed my old profile and ran into a mess of issues with where IMAP mail goes, what data files one uses, which data file is associated with an email account, etc etc. Fortunately all my data was backed up in old PST files. This time I went into the advanced settings for the conduits and enabled sync to multiple PCs. I think that turned off the obnoxious warnings.
1. Click on the HotSync icon in the System Tray (lower righthand corner by the clock)
2. Select Exit
3. Go to the following location:
C:/ Program Files/ Palm/ User Name Folder/ Beyond Contacts
4. From the Edit menu choose "Select All." Delete the contents of this folder.
5. Restart HotSync Manager by going to your Start menu and selecting Programs or All Programs. You will find HotSync Manager will be under your Palm Desktop Program Group.
6. Click on the HotSync icon in the System Tray (lower righthand corner by the clock)
7. Select Custom
8. Double-Click Beyond Contacts
9. Click the 'Advanced' button and make sure the correct Outlook Profile is selected
10. Set Beyond Contacts to "Synchronize the Files"
11. Click 'OK'
12. Click 'Done'
13. Synchronize. During this sync you will once again be asked to select the preferred method. If all of your data is up to date in Outlook like suggested at the start of these steps, you will want to choose this from the Window.
Phew. What a mess. No wonder no-one syncs a PDA at work any more ...