These were very different objects: one a 'space station corridor', the other the heavy door at the end... Given it is not a well-known issue, I shall investigate further. ;-) ( FWIW, weirdness beset me at work, too: I was infamous for the bizarre incidents I'd report, from a hand-sized spider roaming lab, via bird pulling flexible seal out of cladding laps, to cupboards just tipping out their contents as I passed. At home, our tabby 'Poltercats' routinely trump such commonplace stuff... )