> Actually, I am using 3.23.20 on a unix box running debian
> (httrack was built from source, not a debian package).

Can't reproduce the issue using a woody and httrack 3.29.22-
2 (currently in sarge)
What type of sheel are you using exactly? The shell should 
NOT pass the '' (quotes) to the binary, normally.

$ echo $0
-bash
$ which bash
/bin/bash
$ /bin/bash --help
GNU bash, version 2.05a.0(1)-release-(i386-pc-linux-gnu)
..

$ httrack -%F '' localhost/~roche/ 
..
$ httrack --continue
..
$ httrack --continue

$ more hts-cache/doit.log
-%F "" linux/~roche/ -iC1 -iC1
..