My memory's a bit rusty on this (haven't got any Solaris 8 boxes any more), but you may be able to touch /tmp/lp.debug and add an lp.debug<tab>/tmp/lp.debug line to /etc/syslog.conf to get some detailed debugging output in that file. You'll need to kill -HUP <pid of syslogd> to make it pick up the changes.
Remember to turn it off if that works, because the log file can get very big very quickly!
Annihilannic.