I have a HTC Inspire phone that I use all the time. It is “my phone”, I have no land line. One thing I try to do is keep it and my Outlook contact list in sync. The problem is that frequently, the phone does not see the computer or vice versa.
I tried all sorts of things to get it to work reliably, but no luck. I did find that some cables worked and others did not. I would have thought that all mini USB cables were wired the same, perhaps they are. It could be the connectors on the cables or the USB port on my phone is defective.
However, if you are having issues syncing your phone, try a different cable or two or three. Once you find one that works, label it. I also found cables that would charge the phone, show the phone as a disk drive but not sync. Save those for your car or the USB charger and again label them.
If it is truly not the cable then it might be the USB port on your computer or you might need to remove and reinstall the latest version of HTC Sync. Get it from here ( http://www.htc.com/www/software/htc-sync-manager/download/ ).