I must be doing something really wrong here.
I simply drop a TAdvMemo component on a form change the font to non-fixed generate an .exe and then start typing in the memo and the cursor wanders off to the right whilst the text gets inserted to the left i.e. the cursor is not synchronised with the new text.
The other thing I notice is that it is difficult to select a new font from the pop-up Font window - select Segoe UI and close the window you end up with FixedSys as a font name.
Also when you select a property in the Object Inspector the selected property name is highlighted in the system fixed font in bold.
I have used TAdvMemo many times in the past and never had a problem like this one.