It's sure possible. I've heard dozens of stories on here where V3 owners overclocked too much and lowered their "normal" speed because of it.
(eg. if default = 166mhz, overclocked to 180, caused damage (artifacts) brought back down to 166, artifacts still there, now only works properly at 143mhz.)
Something I want to avoid.

Maybe my best bet is to compare benchmark scores on my 450A with the 5500... if it's too low, something's up.