[#5626] - Currency problems

I can't format numbers with currency format. When i select BigDecimals (at the field and textfield) and set the patern of textfield to #,##0.00;-#,##0.00 , the output values on reports is something like: 621.1200046539 . I'm using CSV files as a database for generating reports.
Checking the jrxml files, we see that are not being saved types of fields.