Replying to Canon 7D User Question

After multiple camera tests I decided to go ahead and purchase the Canon 7D after owning Nikon for all of my life.  I picked it up last Friday from the local camera shop and they informed me this was their last one, and would be their last one for as long as Canon was not making cameras due to the earthquake in Japan.

I put a brand new CF card in and started shooting that night.  An hour or two into the shoot an error message popped up: CARD ERROR: REINSERT OR FORMAT CARD.  Since I didn't want to lose anything on the card I popped it out and back in and it started working just fine. 

Over the course of the weekend the error message popped up more and more often and each time it was harder to get it to work again (ie, this time I had to pop it out, in, multiple times before it would read).  Tuesday night going out to shoot a sunset skate the error popped up once more and would not go away no matter what.  I borrowed a friend's extra CF card (different brand, also brand new, still in packaging) and we went on our shoot.

An hour into the shoot, mid video clip, the error message pops up again.  I took the camera back to the store yesterday morning and they kept it overnight.  If they have to send it in to Canon I will have to just return it because I need a camera for my summer camp job as a videographer, and they said Canon has no cameras to send as a replacement.

My question for 7D users is have you ever heard of this happening in any 7D with any kind of card before?  If it's a common issue and I just need to find the right brand of card then I could possibly work with that, but if this is a manufacturer's error then I am SOL for now.

CLIFF NOTES:
CF Card will not read in the camera.  Common bug or unheard of??