There really seems to be a great deal of variation in the card slots on the K-7. Some people never had a problem, for some it got better with use (like mine), and for some maybe they never had a physical problem per say but find it awkward to get to. For me, it was an absolute bear to get the card out at first. The only way I could do it was to get my nail in the little slot, and when it would come out it would go FLYING across the room because it took so much force. It didn't seem like it was getting any better for a while even though I was working it in and out a lot, but it did. It never got to the smoothness of my K10D or K100D, but after a couple weeks I could get it out normally with my fingertips.
The other thing to watch out for is when you put the card back in make sure the orange light flashes twice, if it doesn't you'll have a card error when you turn the camera on. It never fails when I look for it to flash it always does, but if I don't then it'll happen.