I've tried using VCast Manager to sync music to my HTC Rezound but can't do this. When I plug my smartphone into the phone dock I choose Mount as Disk Drive but the music doesn't sync. I wanted to create some ringtones from the music I have.
I would suggest to not even bother with VCast. Just drag and drop music to your phone and I believe the stock music app has a ringtone trimmer built in (long press the song you want to set as a ringtone [I would check this on my Rezound, but my 4 year old is playing Angry Birds right now]). Otherwise, you can get a ringtone trimmer app from the market.
If you really want to use VCast, I think you have to select the PC Sync option, but I'm not totally positive (again, Angry Birds).