Hi Jeff,
Looks more like a bug to me in the conversion. It looks like a deep copy, or something similar, has happened. Wait for Geoff to answer your question, or (to be sure) post a bugreport (see menu on homepage).
There is no way to hide objects in the projectbrowser. The project browser always contains all the items of the project, the possibility to hide them is highly unwanted. That could lead to uncontrollable duplicates, forgotten objects, etc., etc.
By the way, I guess you mean "class" instead of "object"? If not, the occurred situation might be "logical" for the conversion, nevertheless not wanted.
Greetings,
Tjerk