Ugh, I have the same problem with my girl, but she's almost 10 months old. She does run on her wheel, but only occasionally. She used to run a lot more when she was younger, but always at kind of a slow pace. I switched her to a CSW, gave her her own completely dark and quiet room at night, everything! When she got her own room she ran for nine nights in a row (the most she has done in a long time), but at that time it was a new house and I guess she was stressed because she hardly ate or drank. But then she stopped running and it seems that out of the last week and a half she has ran only one night! And she is getting heavy! It's been this way for a long time-- she runs on random nights or for a few nights in a row and then doesn't for a long time, and it frustrates me so much because I don't know why! And she won't play with toys! I have an odometer that I have to hook up, and I want to set up a night vision camera on her very soon to see just what is going on with her!