[git commit 3cdce08c24d3cef7f242214f2b48763242a2ead6]
Please have a look at the output of
```
\new Score \with {
\consists "Balloon_engraver"
} \new Staff {
\balloonGrobText LedgerLineSpanner #'(1 . 1) "ledger line"
c'''1
\balloonGrobText LedgerLineSpanner #'(1 . -1) "ledger line"
c'''1
}
```
There are two problems.
(1) The first balloon points to a position that is not related to the
ledger line of the first note. The vertical position is off, too.
(2) The balloon for the second note is missing.
If I'm not mistaken, there are bugs :-)
Werner
