It's all part of the conspiracy Nubi, when nvidia were making the nf3 chipset they had a big meeting.
"hmmm seems like that nubius bought a new 6800GT AGP card"
"that means he'll probably end up with a dfi nf3 eventually"
"HEY! why don't we screw him over by limiting the overclocking potential on GPUs running the nf3 chipset!"
"of course! it's so simple"
"mwahahahahah"
"mwahahahahaha"