VoltaBracket padding

[Tiago Morin]

Hi lilyponders

I don't know why the voltabracket is printed on the text. Anyway the
manual padding is not working.
\version "2.10.33"
\paper {
  raggedright = ##f
}
\score{

\new Staff{
c'4 c' c' c'
\override VoltaBracket #'padding = #5
\set Score.repeatCommands = #'((volta "1."))
<f c' f' a' c'' f''>2^\markup{\center-align {\italic
I}}^\markup{\center-align {\smaller 6}} e''8.[ f''16]
\set Score.repeatCommands = #'((volta #f))
}}

any ideas?

Thank you

Tiago