Please take a look at the attached Java class and the attached PNG files. Please note that the test currently requires two fonts files which I can not provide. It should be easy to exchange them with other font files.
The problem is that the index is not correctly updated and so the second char does not get the correct font. Which leads to an incorrect rendering.
I have also attached a patch.
The current SVN version (# 1543214) also shows the bug.