Sorry it has taken so long to get back to you. Your suggestion did work. Thanks. However I still cannot screen movies downloaded via itunes becuase I connot get the itunes icon up on the TV & when I hit it on the MBpro it disappears from the TV screen. What am i doing wrong. I have screened slideshows from iphoto successfully.
Here is what may be going on, although I'm not 100% sure based on you description...
If your HDTV is connected to "extend the desktop" (not "mirror"), it is acting as the secondary screen. Your MacBook Pro's display is the primary screen (the one that shows the Menu Bar and Dock). When you use full screen mode to play the movie in iTunes, iTunes initially defaults to showing it on the screen that is considered primary. Therefore, the movie may appear on the MacBook Pro's screen, with the HDTV screen showing nothing.
If that is what happens, right (Control click) on the movie playing on the MacBook Pro's screen and select the command to Play Video in Separate Window. The movie should now be playing in a window instead of at full screen. Drag that window from the MacBook Pro's screen to the HDTV screen. With the window completely on the HDTV screen, make it go to full screen mode again. This time, it should use the HDTV screen for full screen mode.