I have installed a postgresql 9.1 and postgis 2.0 from source.
Now I compiled and installed pgrouting 2.0 (after one hour searching the dependencies).
I created the extension on my database in postgres.
I included the function from the sql files pgrouting.sql
But the functions I need are in pgrouting_legacy.sql and pgrouting_dd_legacy.sql
The error output is : psql:/usr/share/postgresql/9.1/contrib/pgrouting-2.0/pgrouting_legacy.sql:299: ERROR: type "geoms" does not exist
Postgresql and Postgis are working fine...
I followed this documentation : http://pgrouting.org/docs/1.x/install.html
http://www.bostongis.com/PrinterFriendly.aspx?content_name=pgrouting_osm2po_1