Well, I got mine from scan.co.uk. It's Crosair Value stuff, but don't let the 'Value' tag put you off, it's done me just fine. My systems stable and I've run memtest from the command line and it passed just fine.
this reminds me of a story i heard where someone cut a huge chunk of a graphics card off to fit into his slot (dont know if it was AGP or PCI or PCI-E) but he'd got the wrong type for his machine and thought chopping a part of it off would make it work. Needless to say, it didnt work and he was left clueless as to why not.