Thanks for responding so quickly, Daniel! Removing the .wine folder didn't make any difference. Removing the files (can't remember exact names) under .config/menus did! I think that the default Gnome menu editor is bizarrely named 'Main Menu' (in Ubuntu) with package name 'alacarte', but I could be wrong. An annoying deficiency of Gnome IMO. C'mon GUI designers, tell us wtf is going on.
