in XEmacs 21.2 (beta16) "Sumida" [Lucid] (i586-pc-linux) of Mon Jun 14 1999 on ltrpluim changing the font family from the menus causes "Wrong type argument: number-char-or-marker-p, nil" to be signalled in font-menu-set-font. The following patch fixes it for me, but I don't know if it's the right fix. Robert Index: font-menu.el =================================================================== RCS file: /usr/CVSroot/XEmacs/xemacs/lisp/Attic/font-menu.el,v retrieving revision 1.1.2.3 diff -u -w -u -r1.1.2.3 font-menu.el --- font-menu.el 1999/06/11 03:04:55 1.1.2.3 +++ font-menu.el 1999/06/17 16:49:41 ＠＠ -400,7 +400,7 ＠＠ (list :family family :size (concat (int-to-string - (/ size + (/ (or size from-size) (specifier-instance font-menu-size-scaling (selected-device)))) "pt"))) -- The above are my opinions. Take them or leave them.