If you are running Backupmenu, I would say you should try restoring a backup from better times. If not, I agree with the idea of reflashing.

Personally, I have done well with the philosophy of recklessly installing whatever programs I want whenever I want and not paying attention to whether they come from extras-devel or whatever. My N900 runs great, and so did my N810 and N800 with the same philosophy. But if I do start running into mysterious problems, I reflash without concern or complaint.