This has happened to me before. Donāt move the time backwards (such that the date changes) and donāt change the time between 9 pm and 3am. The 7750 does not react well to doing these things the problem you describe is quite common.
Will let you know if they deem it a "user fault" or a "defect" and I'm assuming that IWC will rectify the problem if it's a defect. Naturally, if IWC deems it's a "user fault" then I will be paying IWC to rectify the defect.