Thanks - will look at this, and get back in touch if it re-occours. (There is a chance it might be unrelated - PC stability possibly questionable).

I'm not sure it adds much, but at present all I have is the following

Do you know what a "Fatal Error 252" means?

Its just appeared on a run on a fairly new TC-08 USB, which had been running without any problems for around a week before that point.

Thanks,

Simon