hortsy,
First of all, what version of Project are you using? And is it in an enterprise environment (e.g. Project Server or Project Online)? Are you using a resource pool file or is this a stand-alone Project file with it's own resources?
For reference, assigning resources from the drop down in the Resource Names field is not the best way to assign resources. There are a few different best ways to assign resources including using the Assign Resources found under, Resources > Assignments > Assign Resources. Do you see the added resources when you use that method?
John
