placement of rehearsal marks

[Helge Kruse]

Hello,

I have a glissando that goes to anywhere, written with hidden notes. 
Unfortunately this clashes with the next rehearsal mark. How do I get 
the "B" to the same Y-position as "A"?

Helge

\relative c' {

  \time 2/4

  r4 c' | \mark \default

<< {

    \hideNotes

    c4.\glissando

    a''8 \unHideNotes

    }

  \\ { c,,2 } >>

  \time 3/4 \mark \default

  a4. c,8 f a |

}