Scott, My doctor just reset all my basal rates. Now I am experiencing the same thing (for me only in the afternoon/evening). So I figure that my basal rate is too low then. I think that Melissa is right that is likely the case. The same thing would happen with injections if you weren’t taking enough of your long acting insulin (Lantus, Levemir, etc).
Your pump is only as good as the settings that are in it!! So you have to get your basal rates right. If you just started on the pump, then you will need to do basal testing. That means fasting and not bolusing for at least 6 hours and seeing what happens to your blood sugars. They should stay level. If they are climbing up, then your basal is too low. If they are dropping then your basal is too high. The book, Pumping Insulin, explains how to do basal testing really well. Once your basal rates are set right, you will be a much happier pumper (really it’s amazing!)
But the road there can be frustrating because you need to figure out the right settings. One thing that might help is to see if you can get a trial CGMS even for 3 days. It makes basal testing even more useful. Hopefully you can get your settings adjusted soon!!!