You might try right clicking on a video while it is doing its thing and choose settings and then the "file folder" at the bottom with the green arrow going into it? and see how much space you're allowing them to store stuff on your disk; that might not be high enough. Mine is set at 100kb and is fine.
You got the latest version of Adobe Flash player? 9.0 I think it is? That's what I have:
http://www.macromedia.com/support/do...lp/help02.html