implementation problem

Hi
I am having problems to set up your plugin.
I would like to display all articles but only from a single specific category on every pages: index and categories but i can’t reach this.
I got the alphabet ok but when i select a category where there is no article starting, for exampe, by T i got “result not found” instead of pulling the article from the category i want…
Could you, please,let meknow how to set it up exactly to get what i want?
thanks
Lola