I've been doing a lot of searching and while a lot of forum posts say this shouldn't be possible, something is most definitely broken with the watch.
A few days ago, I accidentally changed the time backwards (which I never normally do) when it was winding up to the change the calendar. When I put the watch back on I realised it was completely misaligned.
It's a 3 year old Tissot Le Locle Automatic with an ETA 2842-2 Caliber movement. As it's hard to fully explain how weird it's behaving, i've uploaded this video. It's pretty long at 4 min as I go through 2 x 24 hour cycles (and I get tired of manually winding it). The most important part is the last 30 seconds.
Is it completely busted or could it be fixed?