I found that if you edit the new.ndx file in the 
cache, and remove all the "index" html file entries, 
you can update a website without downloading 
everything (on servers where the "update" option 
doesn'T work).

I used the textpad regular expressins in textpad.

Textpad Search string //
\n.*index.*\n.*\n.*\n.*\n.*\n.*\n.*\n.*//
Textpad Replace string //

Hope it helps!