Try this, Bernard:
Start SBCL in a terminal - not through Slime.
(require 'swank) (swank:create-server :port 4007 :style :spawn :dont-close t)
Now start emacs, and connect to the running Lisp through swank on 4005:
M-x slime-connect 127.0.0.1 4007
Cut the following from this email and paste it into Slime's REPL and evaluate it:
(elt "☺" 0)
When I do that Slime dies and the Lisp says:
;; swank:close-connection: end of file on #<SB-IMPL::STRING-INPUT-STREAM {1002FD93B1}>
Actually, it frequently dies before I can even evaluate it. Just having that character in the buffer kills the connection.
Jeff