Error not callable with argument types but types matches

[Sliya via Digitalmars-d-learn]

On Saturday, 7 November 2015 at 17:27:00 UTC, Adam D. Ruppe wrote:
> Are you sure it is the same Noise on both sides? Two separate 
> imports might define different interfaces with the same name 
> and that could be what's causing the confusion here.

You sir are my savior !
I imported "Noise" instead of "noise". What I don't get is that I 
have no file named "Noise", so why doesn't the line import Noise; 
throws a compilation error ?