Thinkpad W500 / ATi 5700 (Discrete) + Ubuntu 10.10 media playback issues

So I usually have my Thinkpad W500 configured to use integrated graphics but have since activated the discrete (ATI FireGL V5700) video card via the BIOS/fglrx drivers to enable Displayport. Everything seems to work fine, the desktop clones to the LCDTV to which my laptop is connected however when I attempt to playback any media (using VLC, Movie Player, etc) I do not get any image (only sound - and that only on my laptop speakers even though I'm connected to the LCDTV via Displayport-HDMI).

I've tinkered around with the Catalyst video settings but cannot seem to get any video media working (.mkv, avi, mp4)...

What am I missing?

Also, is it possible to disable the proprietary ATI fglrx driver without necessarily uninstalling it? I know that there are switchable graphics workarounds for the hybrid controllers on this line of laptops but I haven't mucked around with them in quite awhile.

Any advice would be much appreciated...

Thanks!

anybody... anybody... Bueller?