[slime-devel] fuzzy completion on buffer names?

There was a time when fuzzy completion was working on while typing buffer names. For example, I could just type "repl"and not have to type "*slime-r" to disambiguate various *slime... buffers. I don't know if I did something to turn this off or I need to do something now to turn it back on, but I miss it. I have searched for the setting without success. Any advice? Thanks Jeff