I started using HTTrack and it works great. Specially because with rules I can
decide exact what I want to DL and what I don't want. But lately for images
stored on imagevenue.com, it doesn't work very good, because on imagevenue
links change very often. So HTTrack DL only 25 out of 24 files. I tried to use
the option to not purge old files and tried running it several times, but I
didn't manage to DL all files.

I think that the problem is because HTTrack first collects all external links
from source page and then it go parsing. If there are many links to images, it
need some time to DL the image and in meantime some links to images change. 

Is it possible that HHTrack would follow the link (which must match to rules)
as soon as it find it?