Certified digital speedometer

The digital speedometer on my 1991 9c1 has been acting up. I don't know if it's the cold weather or what but when I first start the car in the morning, it takes about 15 minutes for the speedometer to register. Once the car has been running, I could shut it off and start it again a few hours later and the speedometer works fine. It's just after the car has been sitting all night that I experience this problem.
Should I get this checked out or is it just a problem of colder weather that I'll have to deal with? Thanks.

mine did that as well, it took it a part and removed the center computer chip and cleaned it it rubbing and have not had a problem since.