You Tube woes...

I'm experiencing a rather annoying problem and wonder if anybody else is or had experienced the same and if they rectified it. If you rectified it, how?

Videos playing for me on You Tube are hit or miss the past couple of days. Before, they'd play with no problem whatsoever. Now only maybe two out of five videos play properly. With the others I will get them loading (you know, the little circle going round and round) or they flat out say the video is no longer available when I know for a fact that it is. Why is this?

I have the latest Flash player, Java is up to date, cache and cookies are clean as well as all internet temp files.

Help?