Non KTM Panniers to 990 Adv

I've asked a similar question on www.ktmforum.co.uk but not really had any satisfactory answers so thought it might be worth asing here. Has anyone fitted any non KTM panniers to a 990 or poss 950 adv. The reason I ask is that on my previous bike I had metal mule panniers. When I bought the KTM I though it would be just a case of buying the new racks and fitting the panniers but unfortunately this has not been the case.
The Metal Mule Panniers rack fits to the the two bolts of the rear rack and then to the back of the pillion footpegs and then both sides join at the back behind the numberplate. The problem I have is that I cant get more than one bolt in as the holes are so far out and the bar at the back would be covering the numberplate.
I have spoken to Paul at Metal Mule who says that due to the manufacturing tolerances of the back parts of the bike being large bikes all differ and this can cause problems. I'm not really complaining (yet) as Metal Mule have said that if I send back the rack I have they will send me another to see if it fits but I'm just wondering is this normal or am I just unlucky.
I did have a few problems fitting the GS rack but expected to fit panniers to a bike built in a tractor factory would be a problem, but I did think the KTM would be a different story.
Any problems of trouble and strife much appreciated as it will make me feel much better.

If the rear sub frame did differ by more than a few mils from bike to bike, then wouldnt KTM own rack's be equally affected?

Tbh, I think what Metal Mule are saying is true, but it seems that other manufacturers have compensated for it in their design.

I was going to say that maybe the Metal Mule's were made for the 950 - but Im pretty sure that theyre both exactly the same as far as panniers are concerned.

My mate had the Gobi's fitted to his bike, nice - but they dont arf stick out some! I think I'll stick to a roll bag...

Mike