Only show posts in current category - not sub cats

I know this isn't exactly related to my use of Atahualpa but hoping someone may be able to help.

Having just upgraded WP to 3.1 I find the two plugins available to handle my need no longer function.

They are Just One Category and No Sub-Category Posts in Loop.

Does anyone know of an alternative or is there a simple code modification I could add to the loop to achieve the same?

I'm using Atahualap 3.6.1 if that makes a difference.

Thanks for any guidance.