> However, in the past when I have interrupted the download 
> and attempted to "update" 

Note: use "Continue", not "Update" (much faster) for 
continuing a download.

> the partial site NO pages were 
> successfully retrieved.  ALL of them had the standard 401 
> access denied error.  

Weird. Can you activate the extended debugging mode (Set 
Options / Experts only / Debug mode checked) and look at 
the hts-ioinfo.txt file generated to find the first block 
occurence of 401 error to find out what's going on ? (don't 
copy/paste the extract here, as the trace will contains 
your password in the Authorization: field!)