> youtube. I think there should be +*.swf and +*.flv
> in the Scan Rules.
Be default httrack tries to get everything from a site.
get non-html=checked will get all (non-html) files (even from external sites)
+*.swf is only necessary if you don't want all (non-html) files AND there are
swf outside the starting site.

FLV is problematic.  Usually it's not the browser that downloads them, they're
not mentioned in the html. It's the swf that downloads them directly and in
the mirror the swf will try to download the flv from your machine and thus you
get nothing.