Yes, I sometimes have this problem too. Here are some of the suggestions that I received when I started a thread about it:http://petoftheday.com/talk/showthre...threadid=42190. I hope that some of these will help you.

Since I have carpeting everywhere except for my kitchen, I decided to go to Home Depot and buy materials to make a linoleum floor under each litter box. I used wood and then bought linoleum squares. I also put a litter box liner and then a pee pad on top of the linoleum platform in the back of each litter box.

So far it's working out great. I've only had to change the pee pads a few times and I've had the platforms since late Jan.2004. Good luck and please let me know if any of these suggestions have helped you.

Here's another thread that might help you too:http://petoftheday.com/talk/showthre...threadid=37437.