Jazzchords need File > Reload (0.9.6 regression)

Steps to reproduce bug

1. Create or open a score with chordnames
2. Style > Edit General Style > Chordnames
3. Specify "jazzchords.xml"
4. Press OK

Expected behavior: Chord names should visibly change to jazzchord font

Actual behavior: Existing chord names do not change until after File > Reload

MuseScore version: r.2470

(Operating System: Windows XP)

First reported by Xavierjazz: http://www.musescore.org/en/node/3787