Indeed.
The thing is that one piece of silicon isn't ever the same and i have learned this hard way by broking my new computer 5 years ago by tiny first try increse to the clockspeed.
Compared to my year old E8500 that i have been able to do pretty much anything.

There's a reason why Droid is running at 550mhz and N900 at 600mhz. It would be crazy for Nokia to not say no for the overclockers, but of course that doesn't mean your N900 shouldn't work at 900mhz(like mine has for couple of days).

Thought it's no use to come here cry if you fock it up.