Hi Coffefan!
Since I am on injections (How many times did I say that? :)) I find that every probably 3 months I need to re-adjust my lantus -(aka basal rate on the pump) Sometimes I need to lower my lantus because I experience exactly what you describe. I do not know what it is from but I usually contribute it to weight loss or lack of sleep..stress etc. Maybe u need to lower your basal rate. Did you lose weight recently?