> Not stopping the mirror in progress?
Yes.  That seems to be the only work-around. ChessCafe is one of the simplest
websites out there (design-wise) so if httrack doesn't work with CC, much less
will it work with sites with more complicated designs. I hope I'm wrong about
this.

I just thought of something. Can any of you experiment with ChessCafe? Copy
just of few MBs, stop it and then try to resume it or update it.  If it works
for you then it means that perhaps I'm making a user error.