How long have you been using this ROM install (assuming you are on 5.0.7)?
If you have been on it a while, and now you have issues, it is probably because you have maybe installed an errant app that is causing problems.
If not, go back to a Nandroid previously taken, or backup your apps to Titanium Backup & wipe, flash again - there is a new CM ROM 5.0.7.1 out I know.