Installing Unity Asset Server on Debian Squeeze

I used to have Debian Lenny (non-VPS, dedicated hosting) and Unity Asset Server (Unity3D's version control) was running smoothly. But recently I moved to Debian Squeeze (running on VPS) and I can't seem to install it.

I get the following output when trying to install.

 cd: 68: can't cd to postgresql
 home/apps/as/install.sh: 68: ./configure: not found
 make: *** postgresql: No such file or directory.  Stop.
 make: *** UnityExtensions: No such file or directory.  Stop.
 make: *** UnityExtensions: No such file or directory.  Stop.
 cp: cannot stat `unity_build/postgresql.conf.default': No such file or directory
 cp: cannot stat `unity_build/postgresql.conf.init': No such file or directory
 cp: cannot stat `unity_build/pg_hba.conf.default': No such file or directory
 cp: cannot stat `unity_build/pg_hba.conf.init': No such file or directory
 cp: cannot stat `unity_build/db_source.sql.bz2': No such file or directory
 cp: cannot stat `unity_build/db_upgrade_source.sql.bz2': No such file or directory
 cp: cannot stat `unity_build/reset_admin_password.sh': No such file or directory
 cp: cannot stat `unity_build/as_*': No such file or directory
 cp: cannot stat `unity_build/unity_asset_server.sysvinit': No such file or directory
 update-rc.d: using dependency based boot sequencing
 insserv: warning: script is corrupt or invalid: /etc/init.d/../rc6.d/S00vzreboot
 Initializing Asset Server database for the first time: Initializing Asset Server data directory...
     [FAILED]

Do you know what the problem could be? PostgreSQL is installed (just reinstalled it to no avail).