Laptop won't boot after installing new RAM (compatibility issue?)

I bought some new RAM for my Toshiba Satellite P500-14L laptop (max. memory 8GB according to Toshiba website).

• Previously I had 2x2GB Samsung M471B5673EH1-CF8 1066MHz DDR3
• Now I bought 2x4GB Kingston KVR13S9S8K2/8 1333MHz DDR3

I'm using Windows 7 64bit. The system is fine with the old RAM.

Normal mode: With the new RAM it crashes at the "Starting Windows" screen. There is no error, just black screen, all LEDs suddenly off crash. Then it restarts itself and the same thing happens.

Safe mode: It doesn't boot either, it crashes just seconds after hitting the Enter on "Start Win in safe mode". It appears to load some drivers or DLLs and then it crashes with a BSOD:

IRQL_NOT_LESS_OR_EQUAL 0x0000000A 

Both RAMs also fail when inserted one at a time, not only when both at the same time.

Possible causes:

• Faulty memory? I ran the Windows Memory Diagnostic Tool, found no problems. Memtest86+ crashed itself about 4 seconds after it started. By crash I mean, power-off crash, where you hear the HDD stopping and generally everything is switched off at once. I tried to boot into Acronis Recovery (just to try something non-Win), it also crashed the same way (poweroff).

• Compatibility error? Frequency mismatch? Other compatibility issue? How can I check? Which parameter is crucial? The sticks do work in another machine (Acer V5 121 C72G32akk). In that machine they boot up and everything works. I see no obvious compatibility mismatch in the specs so what could be going on?

I also updated the BIOS, although the latest version is from early 2011. No effect.

Could you give me some advice? Thanks.

Certain laptops are very specific on speed of the ram. Buy two 1066mhz 4gb sodimms and it will work without problem. 1333mhz ram is probably too fast.

http://www.toshiba.co.uk/discontinued-products/satellite-p500-14l/

The spec from the toshiba website for your laptop states only 1066mhz ram can be used in your machine, and the maximum is 8gb.