Unstable low memory

I have an ASRock Conroe 1333 that I served well for many years and still does.
It is currently operated with a dual-channel kit of Corsair CM2X1024-6400 (2GB) and I wanted to expand with as little financial outlay my computer to 2GB to 4GB total.
What should I write long, I have bought the cheap memory offered here and they were also immediately recognized properly by the BIOS.
However, the first blue screen was not long in coming and was when you run the Windows Experience Index also quickly reproduce.
Memory out of the system and the rubbish back to Amazon - thanks to great support for reversals is yes, thank God, no problem!
Who knows his time to better appreciate and around EUR 15, - can make more loosely, may be a brand memory (eg Corsair 4GB TWIN2X2048-6400C5C memory (800 MHz, DDR2, CL5, latency 5-5-5-18, XMS2)) Treat yourself and those spared here with the hot needle zusammengelöteten crap!

HANDS OFF!