Hmm, just noticed, i think they are the wrong way around!
When i put the R32 OEM disk on originally, the vents where sweeping forward (as if to scoop up the air), there is a arrow on the disk telling you this... so when i put the ECS ones on, i followed the same principle but it meant that the grooves were also facing forward...
Might be worth emailing ECS to find out Martyn...