I just recently made the upgrade to a nightly build of CyanogenMod (CyanogenMod-7-08302011-NIGHTLY-Fascinate), and I can't seem to keep a steady data signal. I can call and text fine, but every time I attempt to run anything that connects using my 3G data connecting, it instantly drops signal for a random period of time.
I'm not sure what information I'd need to give, but if you need some numbers, feel free to ask.