I haven't contacted Topeak yet ... I was debating about seeing if I still have the instructions for my model of computer first. I suppose I could look online for that too.
But the first time it happened, on my 600K, I thought I must have hit a button or something to cause it to reset, but at the same time I thought it was really weird that it seemed to happen at about midnight. So I really paid attention this past weekend, and sure enough ... 11:59 and .... reset!