in options under the links tab, make sure "Get non-HTML files related to a
link" is checked. under Experts Only make sure that you have "Global travel
mode" set to "Stay on the same address (default)". 

to stop saving other webpages, go to options, Scan Rules tab, on a new line
type -www.* then on a new line put  + then the link to the website you want to
download again, ex. +www.website.com

not sure if this helps because i figure it out just by playing with the
settings until it does, but it's different for each site, so what worked for
me on one might not work for this one. give me a link to what you're trying to
download if you still have issues