After a chinwag with my mate yesterday, a system builder. He said it's possible to get two different branded modules to work in DC, only if the chips are the same manufacturer and there's no branding built into the modules, mainly with the cheap'n'nasty variety of RAM.
He said he had a cheap PC in for upgrade, about a year ago and couldn't ID the RAM that was in it. The customer was adamant that he didn't want to spend more than x amount on the RAM and wouldn't budge, so he couldn't replace the existing module with a new one. Eventually he succeeded, but it took him 6 weeks to find a module that worked along side the other.
