Okay, the whole desktop thing is probably a red herring, as I managed to replicate this without touching my desktop file; but it doesn't seem to be consistent, so I'm having difficulty finding what is actually triggering the behaviour I've been seeing.
Okay, the whole desktop thing is probably a red herring, as I managed to replicate this without touching my desktop file; but it doesn't seem to be consistent, so I'm having difficulty finding what is actually triggering the behaviour I've been seeing.