There's a link on the howardforum board (see the hotlink in the above posting) to a site where you can download a new .plist (
http://www.megaupload.com/?d=9PH5DVRU) I replaced the iSync .plist with the downloaded file and restarted my
iMac.
(the howardforum board has directions for "showing" the .plist in Applications; right click on the iSync application).
iSync immediately recognized my phone via BLUETOOTH and I synched all my contacts wirelessly. I too bought the USB cable but never got it to work wired with iSync and don't need it now.
The download also has a .TIFF of the RAZR, so your iSync panel will have an icon for it.
Took a little trying (I am not used to this level of tinkering) but once I restarted the Mac, voila, no probs.
PS - I am talking about the Verizon RAZR V3c. Good luck.
iMac G5 20" Mac OS X (10.4.3)