> My question is:
> What is the information that your system use to 
> generate the file name?> I know you use a md5 and the original filename.
> Can you give me the algoritm that you use to 
generate 
> the file name?
Well, the *default* one is the is the 16-first bits of 
the md5 of the file absolute path, included query 
string (abs_path+"?" +query, as defined in the 
RFC2396), encoded in hexadecimal:

  /* MD5 - 16 bits */
  strncat(b,url_md5(fil_complete),4);

Example: for
<http://www.foo.com/bar/azerty.asp?a=78>
HTTrack will use:
substring(md5_hexadecimal(/bar/azerty.asp?a=78),4)

But you may want to use the user-defined structure and 
the %[param] command:

The default is:
%h%p/%n%q.%t

That is, hostname+path+/+filename+md5+.+filetype

You can use:
%h%p/%n%[o]%[T].%t

That is, hostname+path+/+filename+o query string 
parameter+T query string parameter+.+filetype

Isn't it what you are looking for ? :))