E8400 EP-45UD3R 4.25Ghz

Hi I have this set up, just purchased recently, curious about a few things, ill post specs first, then what i've noticed, then my question(s)... Thanks
E8400 E0 4.264 (533 Fsb x 8) Keeps my 1066 ram times. 1.350v (could go lower?) Runs stable in prime 1Hr, and everything works ok! :)
EP45-UD3R Motherboard
OCZ Reaper 2x2Gb 1066
OCZ Vertex 30Gb
XFX 5670 (512Mb Non Crossfire ability)
BFG 800+ Watt 4x12v 18A? Rails?

What I've noticed, at 3.6Ghz I could under-volt fine, and run SUPER PI pretty quick, at 4Ghz Even faster! (10-12 Seconds on 1m)

Now.. 4.264Ghz with 1066 ram, lowered timings even, benches higher, but!!!...
With 1Minute + on 1m test? That's getting stupid, how did I go down on PI calculations vs my 3.6Ghz? And such a LARGE variation as-well!

I can Photobucket my Bios screens if ya need, regardless since im starting this thread (my first) Ill attach them for ya anyways for hassle sakes.
http://i998.photobucket.com/albums/a...r/IMAG0182.jpg
http://i998.photobucket.com/albums/a...r/IMAG0181.jpg
http://i998.photobucket.com/albums/a...r/IMAG0180.jpg
http://i998.photobucket.com/albums/a...r/IMAG0179.jpg
http://i998.photobucket.com/albums/a...r/IMAG0178.jpg