Opera 9 and decimal em lengths

I love ems. I set values (using hundredths) like 2.15em regularly. It would seem, however, that Opera 9 either calculates this value differently or rounds up the calculated value. I’ve done a bit of testing today, and adjusted a number of heights which weren’t visually aligned to other things. I used the @media and ~ hack to set a smaller length for Opera 9. I’ll have to investigate this further.