I've know I've had this problem on Win2k; don't recall 
it on Win9x, although I'm doing a lot more mirroring 
now than before.  Win2k tolerates crashed WinHTTrack 
much better than Win9x :)

And yes, I've seen it both ways you describe: before 
and after the details window opens.

I had this problem in v3.16-2; haven't yet attempted 
reproducing it in 3.20beta5.