smaller cautionary accidentals

[Joe Neeman]

I want to change my cautionary accidentals from being in parentheses to 
being smaller. I tried
\override Staff.Accidental #'cautionary-style = #'smaller
but that gave me the following errors:
warning: accidental `0' not found
warning: accidental `0' not found
warning: accidental `0' not found
warning: accidental `0' not found
warning: accidental `0' not found
warning: accidental `0' not found
warning: accidental `0' not found
warning: accidental `0' not found
and the cautionary accidentals did not appear at all.

The example at 
http://lilypond.org/doc/v2.2/input/test/out-www/lily-937991680.ly uses 
the same command and it seems to suffer the same problem.

Thanks,
Joe