Id email them with details of using 2 different types of mem sticks from different manufacturers - what are the sticks u used specifically? - others using this mobo maybe using them and that would be something else to advise them...
Highly unlikely you getting 2 duff sets - I presume it works fine when u just put a 512mb stick in - memtest and all?
They cant ask you to do much else really - so I would definitely ask them to replace it, just makes u have all the facts laid out in front of them - it may take time, but worth doing. Even if you change to another board you could sell the DFI replacement...
I wouldnt leave it as a lesson learnt, just get even and back to square 1, whatever you consider that is...
the memory that i've tried is corsair value select (VS512MB400C3) and Kingston Value Ram (kvr400x64c3a/512) both 512mb,
in dual channel and single channel, the pc boots up and nothing after that happens, just the 4 red led's come on and thats it, to me from what i can make of their vague manual is that there is a fault with the mobo as the leds are suppose to reflect what stage the boot up is in, if it was the ram thats the problem then, would it mean only 2 leds should be alight?????
so how do you go abouts getting dfi to cough up a new mobo?
as their maintaing that the mobo has been tested and working fine as far as they're concerned, should i contact trading standards????
cheers