Config.pm is a package distributed with Perl. As such, this module is the first one found when you use Config;. To fix that, either rename your module (in both the package line as well as your use statement) or place your module's directory first in @INC (inside a BEGIN statement).

I recommend renaming your module -- it avoids confusion. Other modules rely on Config.pm and if they find yours loaded instead, it is likely to break things.

Matt