Problem moving directories on server

[dagr]

Hello,

I have Mantis working on our remote server. When I tried to copy the Mantis files to a new sub-directory and run it from there, I get the following error message instead of the Mantis Login screen:

APPLICATION ERROR #400

Database connection failed. Error received from database was #0: PHP Support for database is not enabled.

Mantis still works if I run it from the original sub-directory. Directory and file permissions look identical.

Any ideas on how to make it run from the new sub-directory?

Thanks