Rounding in financial applications can have serious implications, and the 
rounding method used should be specified precisely. In these cases, it probably 
pays not to trust whichever system rounding is being used by Perl, but to instead
implement the rounding function you need yourself.

To see why, notice how you'll still have an issue on half-way-point alternation:

        for ($i = 0; $i < 1.01; $i += 0.05) { printf "%.1f ",$i}

        0.0 0.1 0.1 0.2 0.2 0.2 0.3 0.3 0.4 0.4 0.5 0.5 0.6 0.7 0.7
        0.8 0.8 0.9 0.9 1.0 1.0