I'm just working through tutorials just now, with pre-built, basic scenes.
It hasn't done it the last few times. Just something I'll need to keep an eye on. Hopefully when I come to render my own scenes, it won't appear. If it does, then I'm in trouble.
Anyway, got some more questions about Maya which I am going to post in a new thread, if anyone cares to lend a hand there.
Thanks for the responses.