N6010 - MR9700 O/C Survey

I'd never O/C'd a mobile GPU before .. always seemed insane given the thermal constraints. I did decide for fun to run some stress tests on the MR9700 on this N6010 though. I decided to leave the test limits at 500/300 with increments of .25Mhz.
My results:
After 63 minutes core at 500, one artifact. Reduced core to 498 and tested for 90 more minutes without artifacts before ending core test.
Tested GPU RAM at 300 for 62 minutes, no artifacts, wife said I needed a shower so I killed the test .

Ran the following profiles in Oblivion (848x480, Medium textures, Bloom) for 1 hour stretches:
460/260 and 460/270 ran without issues.
460/300 gave me a suspicious incident (looking like minor RAM artifact) after an hour which I couldn't reproduce in Oblivion elsewhere or with the ATI-Tool immediatly on exit.
Also ran 498/300 for about 10 minutes before chickening out.

Typically I wouldn't consider running an OC'd laptop GPU, however I am curious why the RAM is stock clocked to 220 when the ATI spec is 260? Especially given the ventilation and apparent ease of clocking the RAM to 260.

Has anyone else OC'd their N6010/MR9700 for long periods of time?
The 460/260 overclock (or normal clock!) boosted performance 4-7fps so I'd like to keep it, but want to be sure of safety.
Also don't want to apply artic silver et al until the warranty is finally out

Any comments?

No artifacting problems here, unless I make 'em

Just browsed that board, 8790 sounds like a piece of crap. Bad ventilation and cheap gpu RAM? Bad mobo? The (non-visual) artifacts I induced by OC-ing the core by 11% and one visual RAM artifact by OC-ing it 36% for a long long stretch of time. I was actually damn impressed with the Fujitsu engineers.
RAM sensitivity is down to the quality of the DDR provided by the notebook manufacturer and ventilation. Preferably the GPU should have a dedicated fan/vent given it's the second most prolific source of heat (perhaps the first now with Pentium Ms and Core Duos ..).
There's one of three reasons RAM is clocked lower then spec. (1) Thermal considerations (2) Voltage considerations (3) Cheap DDRs. I'm sure it's not 3, and suspect it's 2.