I have tried several times to watch YouTube videos on Opera Mobile 8.65 Beta but it is still choppy at best, plus the screen is so small on the Opera page. If you have favorites on YouTube, what I suggest is something I have been doing. Download the YouTube video onto your PC had drive using this website:
http://www.youtubex.com/; don't forget when you go to save it, to put the file extension .flv onto the end of the file name. Then install the new flash plug-in for the TCPMP on your Axim. Transfer the new .flv file you just saved onto your Axim and it opens and plays flawlessly and you can watch it full screen. beautiful!