Oh deary me. To quote myself. (about the MS anti-virus.)
I loaded it on the spare drive, and all seemed very professional.
This (secondary) drive fell over this morning.
It had a bit of history, but was formatted, Partition Magic loaded, and had seemed good as the backup drive ever since. Booted it in XP a few times in the last few days, loaded Sp2, and the above, and this morning it won't get past the first few lines of any of the restore options. Not even command prompt.
So, a few possibilities, but I guess I'll never know.
First symptoms were CheckDisk. But I'll not drift too far on this thread. Any other users of this anti-virus finding that this happens, let us know.