Constant Kernal Crashes after 8 gig RAM card added

Hello everyone - I have a mid 2010 27" iMac and just added 16 gig of new ram (first two slots came with 2 gig each and I bought and had installed two more 8 gig - so I can run Final Cut Pro X) Well, after the new RAM was installed by an apple certified dealer - it kernel crashed about 5 times randomly, which it had never done before - It was obvious it was caused by the new RAM - I took it back and they replaced it - and it has now kernal crashed 6 times - Are 8 Gig Ram cards not compatible with 2010 imacs? These guys seem like they know what they are doing - but enough is enough - I know in Apple's literature they mention that only 2 and 4 gig upgrades are possible - but they said the 8 gigs just came out - what do you guys think?