I agree that tvcplayer was a great app, I used to use it often. Mine used to work seamlessly at stock speed, but for the past few months it had begun to slow down to only one or two frames every few seconds (audio OK). When that first happened, I tried overclocking, but that made little difference - less bad, but still totally unwatchable.

I assumed this was probably a combination of my n900 (2yrs old, never reflashed) losing performance and (maybe) a change in the stream bitrate, and just gave up on it. However I tried again last week (I was interrupted whilst watching something that I didn't want to miss on my big screen TV; had to leave the room, and I thought I'd use tvcplayer to at least follow the audio while I was away). To my surprise, the video was working much better again - several fps at stock speed. I overclocked to 850Mhz, selected the "quality" preset, and it was nice & smooth :-) There has been no change to my n900, so I'm assuming (again) that the improvement must be down to the stream.

So, if you haven't tried for a week or so, try again now. If you find it's now borderline watchable as opposd to frozen (and you are OK with potential impact on your CPU), overclock to 750Mhz or above and it will hopefully be a lot better.