I'd take it back surly it should come with a year's warranty from what I can tell my car has had a rev g since new 08 plate with 30k miles
Very true, I've contacted
http://www.germanautopartsdirect.co.uk where I purchased it from to see what's what.
Only thing I can think of, is the K03 get stupidly hot and cooks the little rubber diaphragm being sat right on top of it, where as the K04 has the relocation of the DV --- perhaps Rev.D or DV+ is better suited to a tuned K03.