Down Problems

I have had a few down problems again where Wyatt gets up immediately from his down into a sit. I am not sure if this is due to:

a) colder floors
b) practicing sits much more than downs lately
c) a physical issue
d) unknown and mysterious dog thoughts

I am having him checked out next week for physical issues since I was seeing some possible jumping issues. If the issue is colder floors, I should not probably not practice unless it is warmer or I put something down. If the issue is not practicing, then I should just practice more, which is somewhat in conflict with "a". He has been better the last few days as I have kept the downs very short and in sight. He did great last night and did a 3.5 minute out of sight sit. I had Tibby crowd him as well for the other stuff hoping to get him more used to judges who stand close to the dogs. I just printed out a premium for mid-March. That will probably be our next attempt.