Please, just use integer (i.e. fixed point) arithmetic for financial data and stop writing shoddy code. It's a no brainer, really...
Floating point arithmetic which can represent the integer values exactly isn't going to give a different answer than fixed point arithmetic. Look at all the actuarial programs written in APL, whose numeric prototype is a double precision float or complex.
So you're saying as long as we stick to representing integers with floats, there will be no problem with inaccuracy? (You're quite right in this assertion).
If it's true though, why bother using floats at all? They are only exact when not using fractional parts, so why not remove the danger and used fixed point integers and save ourselves the wasted bits of the exponent in the float representation?