The differences in the way win7 does security could be blocking clockgen from actually making changes to your system, or blocking it from reporting those changes the way it would in vista or xp. As great as it works, win7 is still pre-release software so almost nothing we're running is actually intended for it. I'd verify with cpu-z that your OC is actually sticking. It could also be that "AMD Sempron 3400+ 1.80Ghz" is just the official 'name' of your processor and that is why it is displayed that way. Mine says "Q9450@2.66Ghz 3.20Ghz", but that could be because the intel chip reports differently or because it's a BIOS overclock.