Playback repeats

I'm trying to make a score play through from bars 1-25, 2-25, 2-25, 2-24, 26-28
(ie. Play three times through then skip bar 25 on the fourth playback and continue from bar 26 to the end.)
I've attempted to use voltas to do this. I have set:

Volta Properties bar 25 -
Text 1.-3
Repeat list 1,2,3

Bar Properties bar 25 -
Play count: 3

Volta Properties bar 26 -
Text 4.
Repeat list 4

Bar Properties bar 26 -
Play count: 2 (greyed out and I can't change this)

Is this a bug or am I simply not using voltas correctly?