What database are you using? What is the difference between Empty and Null?
SQL Server 2005.
NULL means no value
Empty means a String with no data.
You can perform calculations on Empty values, but not NULL.
It's just how FM handles NULL.. It uses an empty string.
Sorry for the long delay on this. If you can confirm a genuine change in behavior, you should report it to Filemaker. In the mean time, can you insert something like the text "NULL" in Filemaker and then have a SQL Trigger replace that on updates to either a real Null or empty string on the back end?