Video issue in vimeo, youtube

I'm having a global issue with video on the ipad, both on vimeo and in the youtube application.

At some point, the buffering stops and won't start again. When it reaches the end of the buffer, the video and sound stop but the little "time elapsed" indicator keeps moving, although nothing is playing. Once I hit pause, it won't start playing again (even in portions of the video that are already buffered), although the "play" and "pause" icons indicate that it's in play or pause mode.

Has anybody else experienced this issue? Any fixes?