No, I don't think this is a problem, as for it to be a problem in perl that would require .5 to evaluate as > .5. That is, if it is _over_ half then it will round, and otherwise it will truncate. It has to go one way or the other, neither way is really right or wrong.
The good news is, add a very small number like .000001 and you'll get what you want.
$a = sprintf("%.2f", $a+.00001);
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