my videos form Iphoto stopped working.
Please clarify. Exactly what happens when you click on the videos? Any error messages? What do they state? The iPhoto users hang out in the iPhoto forums. You may wish to cross-post there.
my mac is running really slow after the update. Is there anything i can do to up the speed of my mac?
Did you repair permissions and restarted your computer after upgrading?
How large is you HD and how much space do you have left?
Check out the following & do the necessary: