Frodo Problems!

I updated to RC3 from a old beta build whcih was stable as hell TBH... really regret it.

Anyway, tried to reinstall back to the old build but can't do it.

Now I've re-installed RC3 and everything seems slower. Not snappy like the last one. Also, everything is broken add-ons wise.. even frodo specific repositries. what have i done wrong?