Permission problem opening database - Mailing list pgsql-general

Hi, I  have done some RTFMing and come up with little on this one.

I have a database that I had setup in the past that I haven't opened for
a while created under 8.1 running the native Win32 port.

When I started the postgres service and tried connecting using PgAdmin
III I got the following error:
An Error has occurred. FATAL: could not open relation 16627/16628/2701:
Permission Denied.

Any ideas on how this can be fixed.

Thanks.