Visual C++ classview problem?

I’m trying to learn me some Visual C++ 6.0 (SP4, Win2K), and have purchased the book “Practical Visual C++ 6” The examples so far are all MFC wizard dialog-based apps, accepting all of the defaults. During the course of the excersises, I notice some odd behavior: When I try to “Add a Member Function” to a button in the resource editor, the dialog class “CxxDlg”, which is the main class for the project, disapears from the classview pane.

A search of Microsofts knowledge base did not reveal anything, and a search of microsoft.public.vc.ide_general only revealed the same question from 19 Feb

Any idea what’s going on, and if there’s a fix? Thanks.