I've just received a M6600 and tried to install Ubuntu 11.04 on the machine with some pretty poor results.
By default the Radeon driver is used for the graphics card however it appears to run very poorly (screen re-drawing visible, tearing of dialogs while moving them).
I installed, through Jockey, the fglrx driver (however I don't know the version that was installed) with even poorer results. All conditions were exacerbated, was almost impossible to use the machine because of tearing while moving windows and typing.
With radeon driver installed, I check with powertop and see that radeon module is 65% of my inturrupts and that I'm using 70w of power (only 1 hour of battery life).
I will check the fglrx module also, however its even more unusable.
Please, any help would be appreciated! I cannot find release notes for the fglrx modules to know if this card is supported.