(define-key slime-xref-mode-map key command)))))
(unless (lookup-key slime-xref-previous key)
(define-key slime-xref-mode-map key command))))))
[did you mean slime-xref-mode-map in lookup-key?]
regardless, no go. it looks like the keymap is generated correctly. it contains (32 . slime-goto-xref) with nothing else assoc'd to 32 or any mention of slime-space.
describe-mode does show what looks to be the proper keymap for the major mode.. with slime-space listed lower in one of the minor modes.
if i change the slime-mode-map to assoc slime-goto-xref to SPC, it does the right thing (for the xref buffer only, of course).
...bryan