Instead of calling compute-restarts directly call an implementation-define swank-compute-restarts. Default that function to call compute-restarts.
In openmcl we would define
(defun swank-compute-restarts (condition) (butlast (compute-restarts condition) 2))
or something more robust, if I can figure that out, to get rid of the restarts that blow away the slime/emacs connection.
BTW, I would make the change myself but my password to the slime CVS seems to have gone bad and mail to the common-lisp.net maintainers has not yet yielded a response. Perhaps Helmut or Luke could help me out...
-Alan