> I tested the page in Firefox but the links work fine
> (at least in my version)
I didn't notice that the links download a pdf file and then returns to the
same page, so I said they didn't work.

> Anyway, why should HTTrack bother? Woudn't it be
> easy to just follow the href and forget about the
> empty onclick?What it should do and what it does are not necessarily the
same.

The onclick is probably irrelevent. The page url is:
<http://www.alkmaar.nl/eCache/INT/21/811.html> but the links are in the form:
<http://www.alkmaar.nl/smartsite.shtml?id=16424>
unless you allow direction up or add filter +www.alkmaar.nl/* you won't get
those links and won't get the pdf's either.