Transcent RAM Compatible with Hynix RAM?

Hi there,

I hope someone can help me with my question. I have two RAM chips which are both DDR II 800 and both are 1GB. Only difference is, one is hynix and the other is transcent. When I put both chips into the same pc they are both picked up and run fine but after some time the pc would crash with the blue screen of death. At first I thought one of the chips was damaged or something but after a whole bunch of multiple RAM tests I saw that both chips are 100% working.

Now I've heard in the past that people say if you put multiple RAM chips in a pc that you should try to keep them the same brand because of compatibility issues involved. I'm not sure what exactly would happen if they aren't compatible with each other though??

So from what I can tell this might a compatibility issue that I'm experiencing. Does anyone know if a Hynix Ram chip is compatible with a Transcent RAM chip?