When I bought the phone, I installed the HTC Sync v3.0.5517 (which was on the SD card and newer than the online version) on my Windows 7 x64 SP1 e never could see it detected by the software. Every time I launched it, the notification icon showed that the phone was detected and after 2 seconds disappeared (htcUPCTLoader.exe also disappeared from task manager).
I tryed the software in a WinXP Virtual Machine and it worked fine, so I decided to contact the HTC Support in order to know if there was some incompatibility with Win7 x64 SP1: the told me that the problem was my PC
After a few search, I found a similar problem in another forum, and tried to rename the iTunes folder, and I finally got HTC Sync starting and synching like a charm. The problem is when the software tries to detect our iTunes playlist in order to show them in the Media synchronization.
I replied back to the HTC Support telling them this issue, hoping that they will fix it.