With Allegro 8.2 on Ubuntu 9.10, the demo lotsa-widgets crashes the Lisp right back to the shell prompt when one clicks the window close box and when one selects (I think) the copy menu item.
Clue: before a little poking around cause ACL to start dying altogether, the close box was just a backtrace showing some tk-format of "~a delete ~a" on a dead menu-entry-radio-button and with format complaining something ws not a list.
Ah, good news of a sort: selecting the copy menu item takes out ACL on Windows as well. Just never noticed since those are...omigod, I think I do a "destroy". "Close window" works under Windows, however. Anyway, Celtk/Linux just needs a little debugging. Proceeding to the 3D Gears example for some eye candy before worrying more on this.