Annytime i started Firefox (ver. 1.5.0.1) i get following error Message:

usr/bin/webhttrack(24238): launching /usr/bin/firefox
Error: Failed to send command: 500 command not parseable
/usr/bin/webhttrack(24238): waiting for browser to terminate..
/usr/bin/webhttrack(24238): nasty signal caught, cleaning up..
/usr/bin/webhttrack: line 168: kill: (24253) - Kein passender Prozess
gefunden
/usr/bin/webhttrack(24238): ..done 

This is the Fix:

vi /usr/bin/webhttrack

Search for:
===================================================
# launch any browser
# if it is a mozilla like browser, check if the browser is running and use
# -remote if needed. Change the URL into openURL($url) too.
# (thanks to Torsten Werner for the patch)
# see <http://www.mozilla.org/unix/remote.html>
if mozillabrowser ${browser}; then
if ! ${browser} -remote "openurl(${url})"; then
log "spawning browser.."
${browser} "${url}"
fi
else
log "spawning regular browser.."
${browser} "${url}"
fi
===================================================
Change Line:
if ! ${browser} -remote "${url}"; then
to:
if ! ${browser} -remote "openurl(${url})"; then

Save !!
start webhttrack and enjoy!!!