The camera on my desktop does exactly the same. It will work for a few days, then not. Uninstall it, the machine finds it, reinstalls the drivers, and off we go again.
Skype on the laptop switches back to MM/DD/YY in the date box in the same way. Go into the control panel, change the date format from DD/MM/YY to DD/MM/YY (nothing actually "changes"), restart Skype, all is well for a few days.
Neither matters, but nor can I find why either does it.
The camera maker says "not our fault, must be MS". Skype says the same.