I agree with Mikel. For a first time sync, it is always a challenge if you depend on Software to decide what is duplicate and what is not. Software cannot read, and doesn't know a lot of things that people know. So a contact Bob Smith and Robert Smith will be considered two contacts. In some cases two legitimate Calendar events may be considered one because they share the same details.
It is better safe than sorry. Better still to always back up before trying new software and a good reminder that if you back up to a CD ROM you have a nice archive in case your hard disk crashes. Just an idea.
CompanionLink DOES HAVE dupe detection. For contacts it matches last name and work phone number. It works pretty good for records that have both. If your records lack those two fields, it works less well and goes very slowly. For Calendar it matches Date, Time and Subject.
I would also suggest synchronizing Tasks if you want. CompanionLink for Google will put them in the Calendar on Google. This is because Google lacks a task API. They work pretty well there, and will automatically sync to the Calendar on your Droid as well.
Alternately, you can use CompanionLink USB to move Tasks and Memos directly to the Droid. In this case, CompanionLink USB has it's own Task and Memo app that works a lot like Outlook on the PC.
I hope this information help, and your one time sync is successful. One time sync is free from CompanionLink. You have 14 days to try it all and get it right. After 14 days if you wish to continue using your Palm Desktop for data entry or backup, you can pay $39.95 for a lifetime license to CompanionLink.
Wayland Bruns, CTO
CompanionLink Software, Inc.
www.companionlink.com