I'm having sync problems too. I was able to successfully transfer a photo from my G4 laptop over to the treo, but it still doesn't sync.
I tried iSync, and while it sees the device, it says "iSync can not connect to this device." The other thing I noticed was that in my Bluetooth Devices tab, when I click on "configure" I get the following message:
"There were no supported services found on your device"
Am I forgetting to do something on the phone? I'm a total noob so I may have skipped a bunch of steps here.
-Ken