> I was wondering if anyone know what criteria/s 
HTtrack 
> uses when deciding what files to update? The help 
file 
> that came along with the program didn't clearly 
specify 
> the criteria/s used...

It is based on the regulat HTTP/1.1 or HTTP/1.0 
specifications (RFC #1945 and RFC #2616), even if some 
hacks have been made (especially the "update hack") to 
attempt to prevent unnecessary updates.. but this 
sometimes don't work, especially with dynamically 
generated contents.