Browser (Firefox) video problems

[jill8beans2]

I am having trouble viewing videos with my browser.

Example, if I go on youtube.com – I can hear the video fine, but it only shows random frames.

Also on some video sites, it tells me that a script is running slow, and do I want to continue or not.

I tried reinstalling the browsers (firefox), and reinstalling flash, but same problem.

Anyone know what the problem is?