1) What ROM were you coming from?
2) How old is your phone? What hardware version is it? What is your hboot version?
3) Did you update your radios, etc. if you had to?
4) Did you wipe cache/dalvik, at least?
If you're coming from an older version of Fresh, you probably could get away with not wiping data, but it makes troubleshooting problems like this kind of difficult. I can't really say one way or the other that that is exactly why it doesn't work. I will say this, though - I've had the camera stop working before due something like a bad kernel flash. The phone worked fine except for that. Reflashing it fixed it, without wiping data at any point. So:
1) Wipe cache/dalvik, then try reflashing the ROM without wiping data to see if it fixes it. If that doesn't work,
2) Wipe data/cache/calvik, then reflash the ROM.
I'd recommend the latter, either way, but it's up to you if #1 fixes it.
