Magento: Products vanished for NON-LOGGEDIN users.

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. Friendly, Rui