ArcGis 10 add field to feature/table fail

I am now getting a "general function" error when I try to add a field to a table. I had no trouble yesterday doing it in the same one that fails today.

I have tried in ArcMap and ArcCatalog. I don't see any errant locked files and I am the only user.

This is a layer with a geodbase. I can add fields to other layer is this dbase.