Probably a bug: wrong bar numbering

[Yury Bulka]

I have noticed that lilypond does print wrong bar number at start of the second
line of my file:
ClarInA = {
\relative c' {
  \key g \minor
  \time 2/2
  \set Score.skipBars = ##t
  bes'1^"Solo"^"Allegro molto appassionato." \p ~
  bes ~
  bes ~
  bes
  (c
  bes)
  R1*4
  |

  d\p ~
  d
  (es
  d)
  % Why lilypond does print 27 bar number here?
  \set score.currentBarNumber = #15
  R1*8
  |
...
}
}

\score{
       \transpose bes a \ClarInA
}

I don't know if it is a bug, or i just did do some mistake in source file?

P.S. version of lilypond on my system is 2.6.3, platform: Debian Gnu/Linux Etch
amd64