I'd be suprised that room lighting messes the Rift up. Unless they've change the tracking technique from CV to S as the original used IR. I think exactly that, they did change the way it tracks. As soon as it failed again last night I went on their help forums (again) and there were several mentions about the tracking requiring adequate lighting. At 7.40 it was light but by 9.15 my room was dark. Hope it is just that as it’s an easy fix.
I honestly thought my broadband would give out anyway as had the BT engineer in the afternoon who told me my fibre was only getting 10mb instead of the 33 it’s capable of
And got crackling phone line, so got open reach coming Friday to sort the external problem.