Hello All,
Running a 1.5.1 here (yes still). Had an issue a while back that has just happened again. I have a category (lets call it 500) with sub categories. I move all product from the sub's up into the main category 500 and delete all now empty sub categories. In the admin all is well, but on the front end I get the "no products to display" message.

In the database all products have 500 as their master category. In products to categories all products have just the one link to the expected 500 category. They just aren't showing up on the front end. If I search for the model of a specific product I get it in search results and can view it. The bread crumb points to the expected 500 category. I click the bread crumb and it says no products.

Please.....

Thank you,
John