trills

[Berthold Gunreben]

Hi,

I am quite new to lilypond and stumbled over a question regarding trills. I'd 
like to use pitched trills which works quite well with something like:

\pitchedTrill b2  \startTrillSpan cis b \stopTrillSpan

However when I want to do a pitched trill over just one single note, I always 
get errors:

test.ly:34:17: warning: programming error: bounds of this piece aren't 
breakable.
  \pitchedTrill b
                 \startTrillSpan cis \stopTrillSpan

Also when doing a second similar trill afterwards, I get different warning:

test.ly:35:17: warning: already have a trill spanner
  \pitchedTrill c
                 \startTrillSpan d \stopTrillSpan

but the trill is not correctly displayed. Obviously I do miss something there.

The version of lilypond I use is 2.10.29.
Any help is greatly appreciated.

Thanks

Berthold