This is very simple.
I have 3 groups of users: Non-logged, normal & Wholesales.
Non-logged and Normal users see one kind of product, Wholesales users see different products.
I'm using 2 Modules to do it: Netzarbeiter GroupsCatalog AND Restrict Categories.
This use to work just fine, but suddenly my site won't display products fro the Non-logged and Normal Users. Wholesale Users products work just fine, and the system isn't broken.
I think it's mainly a configuration problem, but I'm so much into it that I must run over it!
I'm not considering high bids cause the system isn't broken, and there should be no needs for coding.