I can't figure out how the hell you report a bug to Youtube, other than by posting in an obviously-ignored honeypot forum, so I guess I'll just post my bug report here and hope that my LJ is read by a Youtube developer or someone who knows a Youtube developer. (This trick has worked before...)

Dear Youtube,

It used to be that I could press play on the video player and then immediately press pause, to allow the whole video to silently buffer. That no longer works. Now I have to wait until enough of the video has been downloaded that it actually starts playing before I can pause it. This is very irritating, because it means that I can't just press play+pause and then hide the window to come back to it later: I have to sit there and wait 10+ seconds for it to start squawking at me first, then drag the slider to the left, then press pause. Lame! I should be able to press the pause button even if zero bytes of the video have been downloaded.