No such rounding should take place automatically in any version of FIleMaker.
I suggest taking a closer look at the field's data formatting and any auto-enter calculations that may be specified for that field.
Thanks... all is well now, but still not sure what caused it; everything looked the same as another version of the database. So, I imported a new version of the data file (csv) and the rounding problem is gone.
I'd check for an auto-enter calculation that might round your data. The csv import won't trip that field option unless you specifically enable auto-enter options during the import so your re-import may be only a temporary fix here.
Any script that does a batch update of many records in your table might also be the culprit.