Radeon Mobility M6/LY problem

[Matt Casey <mrc8@lehigh.edu>]

Greetings,
I recently purchased an hp pavilion xt345 laptop, which has an ATI 
Radeon Mobility M6 video card.  Following some things that I'd read 
online, I used the 'radeon' driver in my X configuration.  My problem is 
this: about 1/2 the time when I start X, something goes wrong and it 
appears as if some sort of refresh rate is incorrect.  It's clearly 
trying to display the correct thing, but it shows things out of place 
and 'shaking'.  If I switch to a terminal and back into X a few times, 
the problem goes away (until I switch back to a terminal again). 
Sometimes X starts up fine.  The same problems happen when I use 
radeon-fb.  Any ideas on what could be wrong?
I would think that it has to do with the refresh rates in my X config 
file, but I don't understand why it would work fine half the time, in 
that case.
Please CC me in any replies.
Thanks!
--Matt