(double)Slurs on whole Notes

[Thomas Frank]

The follwing snippet shows a very strange behaviour of slurs on whole notes 
which are not placed on the 'default'-side of the note. While the quarter 
notes in the first line are just perfect, the same fails with the whole notes 
in the second and third line.

Is there a way to work around this?

Is it a known bug?

cheers
Thomas

%% BEGIN CODE SNIPPET

\version "2.10.0"

\relative c'' {
    \set doubleSlurs = ##t
    <c e>4( <f a>)( <b d>)( <e g>) |
    \break
    <c, e>1( | <f a>)( | <b d>)( | <e g>) |
    \set doubleSlurs = ##f
    \break
    <c, e>1_( | <f a>)_( | <b d>)_( | <e g>) |
}

%% END CODE SNIPPET

test.png
Description: PNG image