> when my computer crashes and a website download is in
> progress I get the following errors:
> - damaged cache (was repaired automatically; I took a copy
> before I restarted the program to continue the DL and 
tried
> to repair the new.zip with winRAR.

No, don't do that: there are meta-data (HTTP headers) 
inside the ZIP file that will not be repaires, causing the 
cache file to be useless.

And HTTrack is normally able to repair the cache 
auomatically.