can't beam in a quintuplet

[Stefan Thomas]

Dear lilypond-users,
I have another strange problem:
in the below quoted example, I can't have the notes in the quintuplet under one beam.
How can I solve the problem?
\version "2.11.43"
\relative {
    \time 3/4 r2 \times 2/3 {  r8 g b } |
    \time 4/4
    \times 4/5 { d16 [ b f'8. ] }  r4 r2 }