The apache_error.log doesn't record anything when I get this error. When I went to the php_error.log through wamp, it said the file hadn't been created yet. I installed Postgres with PostGIS as part of the OpenGeo Community Suite. I followed the instructions in the link to step 14 and got the following from localhost:
Your PHP installation does not support PostgreSQL. You need to recompile PHP
Forum:
WampServer English