The list of the GUI problems is long, so I'll just summarize some of them.
In text groups, when the writing cursor is moved, the cursor is often not visible at the new position (where it actuall knows it is at), but often remains visible in a trail of places where it previously was.
In Help, the first letter of the search word is usually missing so that it is necessary to start with a space. Also in Help, both the scroll bar and the actual search result list are often messed up with extra lines and fuzzy print.
Actually, I should have stressed that this is a problem in the standard version. I haven't used the Classic version in years. So far no one seems to be contributing on the these or similar problems in the Standard Version.
Thus I have created a new thread for such problems in the standard version.
This thread seems to be completely about the Classic version at this point.