These two issues are different, but the source of the problem is likely the same, Sync Services confusion. What you should do is reset the Sync History.
If resetting the Sync History doesn't resolve this then yo should contact support by go to:
http://www.markspace.com/support/request_palmos.html
You might need to have a workaround to have the handheld overwrite the Mac. Apple doesn't really have a mechanism for that but support can help you work around that.
To reset the Sync History:
1. Go to iCal and click the 'File' menu and choose 'Back up database'.
2. Now revert to the same database you just backed up, click on the 'File' menu and choose 'Revert to database backup'.
3. Do the same process for Address Book click the 'File' menu and choose 'Back up Address Book'
4. Now revert to the same database you just backed up, click on the 'File' menu and choose 'Revert to Address Book backup'.
Steps 1 through 4 are key to the process, they are not just a backup, but the revert part forces a reset of the relationship between Sync Services and iCal and Address Book.
5. Launch the iSync application, found in the /Applications/ folder. (iSync is not used for the sync, but iSync is where Apple handles Sync Services Preferences.)
6. Click on the iSync menu
7. Choose Preferences
8. Click the 'Reset Sync History' button. Read and follow the onscreen directions.
9. This will launch iCal. When the reset process has begun the button will go grey, it is complete when the button becomes active again, but there is no need to re-click it.
10. Restart the Mac