bacula: install problem

[vittorio]

Context: pentium 4, Freebsd 6.0, latest ports with portsnap

Compiling bacula from the ports /usr/ports/sysutils/bacula-server issuing a 
"make install" the installation stops with the following error I'm unable to 
find in the internet:
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if [ -f /usr/local/etc/rc.d/bacula.sh ]; 
then  /bin/mv /usr/local/etc/rc.d/bacula.sh /usr/local/etc/rc.d/z-bacula.sh;  
fi
if [ -f /usr/local/etc/rc.d/bacula.sh.sample ]; 
then  /bin/mv /usr/local/etc/rc.d/bacula.sh.sample /usr/local/etc/rc.d/z-bacula.sh.sample;  
fi
bacula:*:910:
You already have a group "bacula", so I will use it.
pw: user 'bacula' already exists
Adding user "bacula" failed...
*** Error code 1

Stop in /usr/ports/sysutils/bacula-server.
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Please help
Vittorio