Category x-axis tick width is incorrect with 2 categories if longest category name isn't first

I've discovered a bizarre issue where if there are only two categories for a rotated x-axis and the option for axis.x.tick.multiline = false, then the longest category name has to come first in the data provided to the chart, otherwise the width of the ticks will be calculated incorrectly.

As you can see in this first example, the tick content is cut off if the longer category name is not first:
http://jsfiddle.net/b096feng/

But in this second example, where I re-ordered the categories so that the longer category name comes first, the width is calculated correctly:
http://jsfiddle.net/aLhkhbuw/1/