Scan.co.uk refunded me for the faulty Corsair RAM today. Their email is a bit cryptic, but it looks like they ran their own tests with Memtest and found the RAM to be faulty. They never queried me about using the RAM in a Mac or a Mac mini.
Crucial have put their prices up again, so there's a big difference between their RAM and Corsair's (£185 vs £105). I had a bad experience with the Corsair, but if you're on a tight budget it might be worth trying it from scan.co.uk - test it, and return if not happy.
Elliot