Hi NAV User,
well, I can remember a similar question. I went to verify this in a Cronus DB, and found out that it was a "feature" of the IEEE-754 standard and its implementation on x86/x64 processors. There actually *are* scenarios where the exchange rate calculation produces values that are clearly stored on the wrong side of the rounding border a human would apply. Thus, this effect is the result.
The question is can you do something about it? I would say no. You *could* recode the exchange rates algorithm to check with several cleverly chosen factors (2 would be a good start) if you have a rounding issue and do an "error correction", but I guess a mathematical proof would have to come first.
with best regards
Jens