Borda Results Sort Wrong

When ranking poll votes are set to Borda Count and displayed, they sort strangely. First choices with no votes are grouped and displayed, then choices that have been ranked at least once are displayed in reverse alphabetical order. Looking at the Borda Count code, I think the intent was to sort based on points, from most to least (and indeed that seems ideal). Here's the bit I found which I think is supposed to control the sort:

In the ranking.inc file at line 380:

// Sort descending (although there may be ties).
arsort($choice_votes);

However, changing this line or commenting it out seems to have no affect, so I assume something else is actually controlling the sort. Any help would be appreciated.