It's a JavaScript error in this code:
n.replace.call(f.slice(e.index),a,function(){for(var c=1;c<arguments.length-2;c++)if(arguments[c]===undefined)e[c]=undefined})
The problem is that f.slice() is undefined.
This is with Question2Answer installed alongside WordPress 3.3.1. I tried it with both the Default theme and the Candy theme (same results).