Annoying Bluescreens (IRQL_NOT_LESS_OR_EQUA) after adding RAM

Ok, i've just replaced my 8GB 1333 RAM with 16GB Quad pack of Kingston 1600 rams, annoying bluescreen got REALLY frequent.
Battlefield 3 crashes every now and then, even League of Legends that is not known as a resource hog crashed recently.
I've run MEMtest and Vista memory test, both showed that RAMS are fine.
my system specs are:

C2Q Q9550, 2.83GHZ
GTX260 1GB
16GB DRR3 -1600
M/B Gigabyte EP45T-UD3P
1TB Seagate.


temperature - with 100% fan speed temperature of GPU/CPU is around 50*, MAYBE a bit worm but nothing near to critical..
I've installed last GPU drivers from Nvidia.

any idea how can i fix this -_-