Install process, works on 9.04 and 8.04n
apt-get install zlib1g-dev libncurses5-dev groupadd clamav useradd -g clamav clamav ./configure && make && make install
Tailor the following config files to taste:
/usr/local/etc/clamav.conf /usr/local/etc/freshclam.conf
Run clamconf
export LD_LIBRARY_PATH=/usr/local/lib clamconf