Just thought I'd post my findings using myTube and mPlayer v26... I know that other have posted that they are having better luck with the lipsyncing issue using mPlayer v24. I did finally try out that version of mPlayer using myTube and have determined that for my set-up I actually get very near perfect lipsyncing if I use mPlayer v26 and edit the /home/user/.mplayer/config file by adding:

ao=sdl
delay=0.2

BTW - thanks to Serge for the fix in the mplayer thread.

Also thanks a bunch again for making this app!! It's great!!