pedal position

[Stefan Thomas]

Dear Lilypond-users,
in the below quoted snippet I'm not happy with the vertical priority of 
the pedal-symbols and theDynamic.
I would like to have the "pp" , the crescendo hairpin etc. above the 
pedal-signs. But I dont know ho to do.
"\once \override DynamicLineSpanner #'outside-staff-priority = #1" 
doesn't work. What can I do?
Here is the short example:
\relative c''' {
\once \override DynamicLineSpanner #'outside-staff-priority = #1 
c2~\pp\sustainDown \times 2/3 {c4 b bes} |
aes8\< f \times 2/3 {d8-. bes8-. ges8-.\p\sustainUp } r2 | }

Thanks for any advice,
Stefan