> It seems that only for some magazines (in the
> example I have called them with "An" where n=number)
> the httrack is able to get the address for the
> download
> (http://www.zzap.it/explorer.php?album=An&immagine=
> Bn") while for the others no, moreover the download
> of the pages (in the example I have called them with
> "Bm" where m=number) is almost never complete (it
> usually reaches the page B12).

This is because the site is hiding its links in javascript:
< a href="javascript:;" onClick="MM_openBrWindow( '../../explorer.php?album=1&
immagine=78', 'zzap178', 'status=no,scrollbars=yes,resizable=yes')">
< img src="../../zzapmini/1/78.jpg" width="100" height="140" border="0">

First, there is the explorer.php part. That may or may not be a complete url
depending on what the function MM_openBrWindow does with it and the other
parameters. It could be adding other parameters or modifying the path for
example.  Even if it could figure out the real url, there may be no way to
modify the parameters such that the function will get the local file once
mirrored.

Second, the entire function is only executed on a mouse click.  Httrack can't
click on forms.

Third, there is no url there at all.  Perhaps the function sets
document.location.href="SOMEURL" resulting in a page change.