When importing exchange rates with conversion rates of .000000009 or less, the record is rejected with the exception, "The exchange rate must be positive."
We are currently evaluating this issue for a fix in a future service pack.
Steps to Duplicate
1) Create an Exchange rate import process, mapping the fields From Currency, To Currency, As of Date, and Rate. 2) In the import file field being mapped to the rate field in batch, use the value .0000000048. 3) Run the import process and notice that the record is rejected with the exception, "The exchange rate must be positive."