Is it bad to delete the "SyncServices" folder?

I would really like to give you a more substantial answer to the specific question you posed, but I am inclined to simply say, "Yeah, it's probably not a good idea."

That said, you can do this: remove these two files—and only these two—from your user library:

data.syncdb
data.version

You will find them here, buried inside a folder in the SyncServices folder…

Macintosh HD:Users<username>:Library:Application Support:SyncServices:Local

That should take care of the problem. So the most appropriate answer is do not toss the entire SyncServices folder, just those two files inside the Local folder, inside the SyncServices folder.

It's not a good idea at all to touch the SyncServices folder. In fact, there's a specific Knowledge Base article found here ( http://docs.info.apple.com/article.html?artnum=301920) that states:

"As if it were a swarm of bees, you should stay away from the SyncServices folder in Mac OS X 10.4. Removing or modifying anything in it—or in subfolders within it—may cause unexpected issues. (This folder is located in your Application Support folder, in your Library folder, in your Home folder.)

Deleting or modifying things in the SyncServices folder may cause unexpected results such as:

Duplicate contacts in Address Book or appointments in iCal.
Data loss in Address Book or iCal.

Important: Any lost or duplicate data could propagate to other devices and computers via iSync and .Mac sync. This means data could be lost on other computers."

Good luck with fixing your issue.

Dual 2.3 GHz PowerMac G5 (Early 2005) Mac OS X (10.4.8) 2.5 GB Ram, 23" Apple Cinema Display

Adam has pointed out that Apple clearly cautions users that they should not touch the SyncServices folder, though I must say that from my point of view, this was simply the quick and dirty way of saying, "If you break it, you own it."

I'm confident that removing only the two files I identified from the Local folder stored inside the SyncServices folder will not 'break' your configuration, and should directly address the problem you describe. The Sync Services framework is a complex software mechanism, and their warning to users not to touch that folder is generally warranted, but you cannot fix the problem without removing those two files.

I look forward to the day when Apple itself offers an official, detailed list of steps for users to follow to identify and correct synchronization problems. That day, however, is likely far away…

In the meantime, if you're curious, here is an Apple Developer document which explains how the Sync Services framework operates:

http://developer.apple.com/macosx/syncservices.html