Thanks, I got it after all (for the record, it's also 0x1184 on this little Ixus).
It'd never cross my mind to expect, and look for an unnamed (!) event that would mysteriously unlock (!!) the keys! I start to think -- and maybe I suspected it before -- that even the "H" in someone's signature is not all there is to it...
P.S. Regretfully, the later versions of chdkcam don't like my little camera and refuse to connect -- I must've patched something wrong. Strangely enough, mweerden's ptpcam connects flawlessly...