diff -urN trac-0.10.3/trac/db/postgres_backend.py trac-0.10.3.unixsocket/trac/db/postgres_backend.py
--- trac-0.10.3/trac/db/postgres_backend.py	2006-12-12 18:44:07.000000000 +0000
+++ trac-0.10.3.unixsocket/trac/db/postgres_backend.py	2007-01-16 00:16:25.892000250 +0000
@@ -103,6 +103,8 @@
                 dsn.append('user=' + user)
             if password:
                 dsn.append('password=' + password)
+            if params.has_key('host'):
+                host = params['host']
             if host:
                 dsn.append('host=' + host)
             if port: