New RAM

This is a tad embarrasing  

Anyways, I built my last computer last Thursday, its working really well but not quite up to standard. To recap I have :

8800GTS
E6300
Abit IL9 Pro

At stock speeds, now my RAM is Corsair DDR2 XMS2 PC5400 675 mhz RAM.

I have just learnt that my Mobo only supports up to 667 mhz RAM at different timings...

The RAM works fine, but only at a frequency of 340mhz shown here :



Is there anyway I can fix the problem without having to replace the RAM with the 667mhz version.