Whilst running either the stock Froyo or a lot of MIUI Gingerbread ROMs on my Motorola Defy, X-link has always worked fine for exchanging files between it and my Win7 64-bit notebook, but since I flashed eppy's ICS 07.05 build on my phone, my notebook can't detect my it anymore. Hope you get some time to keep it up.
Thanks, anyway.
Have you tried some of the troubleshooting tips yet?
99% of the time, the issue is not in the app. It's very likely the issue is in the ROM you're using and you'll have to take it up with the ROM chef.