Simple problem with MS Access 2000 / 2003.

After the creation of a data base I insert combi and/or list fields into a form. They are linked with tables. So a very simple procedure.
Then when I use the entries of the tables in the combi/list field the chosen information appears everywhere and there is no possibility to put different terms into every dataset.
I'm aware of that there is a very simple adjustment but I can not find it.
If anybody who's an expert wants to help me please do that. Thank you in advance.