Thanks Gaz

I read that too, so it would appear to be a file-type recognition topic.
Given that I only use MP3 (i.e. never MP1 or MP2), I would logically conclude that the worst that might happen would that MP3Gain would misidentify the MP3 and simply refuse to analyse/gain change the file (which has never happened, btw).

Thanks again for the clarfication.

Neb.