The easiest way to check for bad ram is to use micro-scope 2000.
Check it out at
http://www.micro2000.com
It's more than a few bucks but I tell you what it's saved me moocho time in determining bad sticks of mem.
Well worth the investment, if'n you'll be working on allot of systems that is.
If you decide to get it tell em Wizbones PC sent ya. I don't know if I'll get anything other than a thanks from them, but doesn't hurt to try eh?