> It doesn't work because of a Segmentation Fault ...
> I have this message when I debug with gdb: 
> Program received signal SIGSEGV, Segmentation fault.
> 0x4002bde7 in check_sockerror (s=-500000) at 
htscore.c:3036
> /httrack-3.33.03/src/htscore.c:3036:97686:beg:0x4002bde7
> (gdb)

A probable bug in the back_maydeletehttp() function, file 
htsback.c, around line 449 is the cause of this crash.

the line:
&& !check_sockerror(back[p].r.soc)

should be:
&& !back[p].r.is_file && !check_sockerror(back[p].r.soc)

I'll try to release a patch soon - if you can, can you try 
to fix this line and check if it's working ?