Doesn't do anything when I try to seek the video forward or back. Some other youtube videos do seek fine.
Seeks works here, i can go back and forth and i can verify from plugin properties dialog that video is downloading. The problem you are seeing is probably that it won't start playing once the video has been downloaded completely, right?
Closing because problematic video was removed and I can't find any other videos with the same problem.
Change to invalid since the bug wasn't fixed, but the video disappeared