[memory] Problem with SuperTalent WB160UX3G8 and Windows's rating

I just upgrade my system with a X58 MB (Asus P6X58D Premium), an i-920 and the WB160UX3G8 3GB ddr3 kit, and been having the following problem:

Went to re-run the tests for the "Windows experience index" (W7-64bit) and the memory score went down!

I had a e8500 cpu with a 6.6 score, that went to 7.5 with the i7-920.

On the other hand, my memory score was also 6.6 with 4GB (2x2GB) of DDR2 1066MHz Oxx Fatal1ty , and now, with the 3GB DDR3 1600MHz my score is 5.9!!!

Tried a few tweaks with the bios, but with no success.

In the other hand the Everest results are:
15759 - read
13509 - write
17346 - copy
54.0 - latency

Are these values consistent with what I should expect from these modules? The problem is with the hardware (or it's configuration) or with Windows 7 benchmark?

Thanks for your attention.