Thunar don't use the stock_ok icon mapped in the /usr/share/icons/Rodent/iconrc file on some dialog boxes : - Creating a new folder - Renaming a single file or folder As workaround, creating a symlink from stock_ok to gtk-ok solve the problem.
Well, neither stock_ok, nor gtk-ok are standard compliant (the icon naming spec says it should be named "dialog-ok"). But gtk-ok is currently present in nearly every icon theme, so we stick with that until all icon themes follow the icon naming spec.