Thanks, Slarty. I'll give the memory test a go.

The only thing that has confused the hell out of me is that it doesn't happen very often at all. I run the game a fair bit and it has happened about, ohhh, 3 or 4 times. I've had the game for about a year or thereabouts.

I'll take a few deep breaths and delve into it. Better fixed than not, eh?