Why won't youtube.com videos work for me anymore yet some do?

I've had my computer for two years now and have had no problems at all. My browsing experience has always been nothing less than impeccable. I've always frequented youtube.com to view videos. I've never had a single problem viewing videos on youtube.com at all. But for the past three months I have been experiencing strange things on youtube.com. Sometimes I will play a video and it will begin without problems and play without a glitch. At other times I'll play a video and it will stay at 0 seconds for minutes, than advances by 2 seconds every few minutes or so [Basically the video stays stuck and plays in bits and pieces slowly]. I use mozilla firefox to surf the web and the funny thing is some youtube.com videos that won't work on mozilla will work on internet explorer. But internet explorer still doesn't play all videos and some get stuck and don't play just the same as mozilla. I have no idea why this is happening and it cannot be my internet since I have hi speed dsl at 10mbps. I've also never experienced this with youtube.com before and all the videos that don't work for me [which is usually luck of the draw 50/50] work for everyone else on their pcs with lower internet speeds than me . Videos on any other site work for me fine...

What could be the cause of this and how can I fix it?




- Thanks






:cry

 

anyone?