Lets hit the benchmarks
Ok first thing you should do after you install everything is run 3D Mark : if you get a score less than 6500 or 7000 dont worry - this means that your system too came in underclocked - lets leave it this way for the present.
Make sure you install SP1, DX9.0 and then try your luck downloading 3DMark 2003
if you can do this - try to run it with the old (6178) drivers, 6255 drivers from s_seven.net and then with the latest cat 3.1 drivers.
I am going to be doing the same thing.
Oh and install Powerstrip and set to adapter defaults (CPU - 259 and DDR -152)
we will go with this first and then run it at rated specs of CPU-259 and DDR - 182
keep us posted...