would need to look at the actual copy of your minidump file
to see what the actual cause of your problem. Otherwise it is just a guess.
my guess is your browser is using 3d graphics acceleration and your graphics card is not getting proper power when it kicks into 3d graphics mode. (check cables that run from directly from the power supply to the graphics card)
the AMD graphics cards tend to panic when the don't get proper power and return a unknown bugcheck error code to stop the system.