Go to Settings, General then scroll down until you see what version you have.
I have 2.2 and I don't have the problem you speak of.
Also, which iPod Touch do you have- 1st or 2nd generation? (does it have sound without headphones?)
I have the first generation.

I haven't synced my iPod in weeks. I don't use YouTube often, but I like it being there and being free. If it changed during an update, I'm not sure I want to sync it any time soon...