VC lags

[Jerka]

So I got my new PC and of course installed VC to play some while installing some other games and I noticed I had some lags in game, almost like if it was fps lags even though I had steady 30fps, anyway I just though it lagged because of all the installations.
But a few days ago when I fired it up to stunt some I still had those damn lags, its like it would drop from 30 to 20fps and then up again even though the fps thingy from Fraps still says its at 30. I have tried to find some information about this but since it haven't happened in any other games I've played so far its been hard to find any information about it.

So far I've tried changing compatibility to all of the available ones, Changing the monitors refresh rate, tested all the resolutions in game, reinstalling all the drivers, reinstalling VC and installing VC via Steam(if it was a corrupt CD) but nothing has helped.

Any idea whats the cause of this might be?

Specs
Windows 7 32-bit
AMD athlon(tm) X2 250 (2 CPUs) 3.00GHz
ATI radeon HD 5500 Series
2GB RAM

Thanks for reading.

Edit: I forgot to add that this does not happen if I play FL-off or if I record with Fraps while playing.

[Noah]

Hope someone knows a fix dude, be a shame if your solo got any more delayed 

[Kukiel]

I bet it's windows 7. I have it too and my vc doesn't work perfect. For example on my last PC i could use Nvidia's full AA settings. Now i can't because game lags then.

[VaNilla]

Windows 7 is fine, to me it just sounds like your processor doesn't send enough power to the game unless it's running at stress (fraps, FL off). I'm not one to ask though, just guessing

[A maid]

^What he said.

But are you 100% sure you get framedrops and not that you think it is?

[Jerka]

But are you 100% sure you get framedrops and not that you think it is?

There are actually not frame drops since its at 30fps all the time even when it start lagging its still at 30, my brother also noticed the laggs to so its not just me imagining it. 
I've tried a frame limiter for VC and put it at 31fps and then the lags stopped, i have seriously no idea what is causing this...

[Gryzlek]

dunno if its that what you're talking about but i've got that 'laggy feeling' when i play on v-sync on, try to turn it off