Ubuntu applies this [0] patch to roxen4. It may solve the problem.
[0] http://patches.ubuntu.com/r/roxen4/roxen4_4.0.425-7ubuntu1.patch
diff -pruN 4.0.425-7/debian/postinst 4.0.425-7ubuntu1/debian/postinst
--- 4.0.425-7/debian/postinst 2007-11-22 23:13:17.000000000 +0000
+++ 4.0.425-7ubuntu1/debian/postinst 2007-11-22 23:11:47.000000000 +0000
@@ -150,12 +150,13 @@ fi
if [ ! -f /var/lib/roxen4/mysql/host.frm -a \
-f /usr/share/doc/roxen4/examples/mysql-template.tar.gz ]
then
- pushd /var/lib/roxen4
+ OLDPWD=`pwd`
+ cd /var/lib/roxen4
echo -n "Unpacking Roxen4 MySQL database... "
tar xzf /usr/share/doc/roxen4/examples/mysql-template.tar.gz
chown -R 33:33 .
echo "done."
- popd
+ cd $OLDPWD
fi
# =======================================
