When an accountant enters many numbers together that is easier if he does not have to enter the decimal separator. This is common in almost every accounting software in germany.
If you want to enter "123.45" you enter the characters "12345" and when you press Enter it is formatted into "123,45".
This change should be set user-specific because it may be the case that the accountant likes it this way and the secretary likes it the other way.
This function is often called ADD2. See for example: http://support.casio.com/answer.php?rgn=5&cid=004001001004&qid=22663&num=1
We want to set this in a preference (using the preference window in the upper right corner). There is an idea of Carlos Ruiz to redo the whole preferences window: