Added 256MB DDR Crucial PC2700 (512 total)

Added 256MB DDR Crucial PC2700 (512 total), now I got issues...

Okay guys, I have two sticks of RAM...one is a Samsung 256MB PC2700 and I just got a stick of Crucial 256 PC2700 from Newegg today.
Added the stick of Crucial in today now I get error messages whenever I play WC3 something about my RAM...I'll take a screenshot next time I play and post it. But it said something about it can't reading my memory, I've got the timing to 2.5-6-3-3 and my FSB is at 150.

Anyone ever have this experience?

My setup is:
P4 1.6a @ 2.4Ghz
512MB DDR
Abit BD7-II RAID
Built by ATI Retail 8500 64MB

What happens if you put the Crucial alone? Try the Crucial alone w/ memtest 86. If it is fine then they may just not mix.

Where can I get this memtest?

Look in the sticky "Memory stress/burn-in programs"