Cadenzas and grace notes

[Maurizio Tomasi]

In the following example, automatic beam splitting is disabled in the last 
bar.  If you remove "\appoggiatura b8", all goes well.

\score {
   \relative c' {
        \time 4/4

        \cadenzaOn
        c1 ~ \tiny c32[ d e f g a b c d e f g a b] \normalsize
        \cadenzaOff

        \bar "|"

        \appoggiatura b8 c4 g8 e c2
   }
}

I found this strange behavior while writing a multipart score: automatic 
beams were disabled in the other staves as well (and the MIDI output is 
wrong, since the voices are no more syncronized).  This happened also when I 
put a "\appoggiatura s8" in the other staves.

Am I doing something wrong, or is this a bug?

Maurizio.