I think I may have found the problem with my extremely finicky kitty. (I hope). I had moved her litter box from the guest bathroom a few weeks ago because we had company for the weekend (I didn't want my guests stepping in kitty litter as they got out of the shower). I decided after that weekend to leave it where it was in the front hall. Well, apparently, she prefers her box in the bathroom, because I have moved it back and she now seems to be using her box again. I never even thought that she could be that picky!! What worried me was, even though her poop was firm and normal, she wasn't stopping to "dig" or cover up. I hope the situation is resolved, I will keep you all posted. Thank you so much for all of your suggestions!