Puff doesn't usually let me watch her run on the wheel but right now she started running on it while I was in the room and I noticed that she keeps slipping and even falling off sometimes! I think it's because she's running diagonally so that half her body is almost off the wheel. It's a 12" Comfort Wheel and it's secured so it's not like it's pushing her off and I was thinking about getting another one but would that even help if it's just the way she runs? I feel so bad for her though because she's so determined! She tries to run so fast that the wheel gets ahead of her and then she slips and slides off and then hops back and runs even faster like she's determined to beat it! It doesn't seem like she's getting hurt and it's not a big drop and she always lands softly in her litter box so should I be concerned? Or just let her keep doing her thing?