Hi, I now can reproduce the bug it reported lately: xemacs -vanilla M-x ballon-help-mode RET Now for example place the mouse pointer over a toolbar icon and voila xemacs is gone. Here ist the output XEmacs 21.2 (beta32) "Kastor & Polydeukes" [Lucid] (sparc-sun-solaris2.6, Mule) of Mon Mar 27 2000 on inss24 "--prefix=/usr/users/kaage/lib/xemacs --dynamic=yes --with-dialogs=athena --with-site-lisp --with-mule" working with the XEmacs cvs version of today, xemacs crashed suddenly with Fatal error (6) while using VM and left the following message on the terminal: Fatal error: assertion failed, file glyphs.c, line 2917, EQ (Fgethash (instantiator, XWINDOW (domain)->subwindow_instance_cache, Qunbound), instance) Lisp backtrace follows: # (unwind-protect ...) # (catch #<INTERNAL OBJECT (XEmacs bug?) (opaque-ptr, adr=0x2c586c) 0x331000> ...) # (unwind-protect ...) # bind (inhibit-quit) # (condition-case ... . error) # (catch top-level ...) GDB backtrace follows: (gdb) where #0 0xef10800c in _libc_kill () from /lib/libc.so.1 #1 0xa3bf8 in fatal_error_signal (sig=6) at emacs.c:293 #2 <signal handler called> #3 0xef10800c in _libc_kill () from /lib/libc.so.1 #4 0xef0ba4ac in abort () from /lib/libc.so.1 #5 0xa6534 in syms_of_emacs () at emacs.c:2754 Greetings, Uli