Apparently FileMaker has recently released FM 11.0v4, which is compatible with Lion. On the FM site they state:
-OS X Lion only: Addressed an issue with some date field formats showing Asian characters.
-OS X Lion only: Addressed an issue with not being able to use zero or negative numbers in data formatting in the Inspector and in some controls in the Chart Setup dialog.
But in the table about the upgrade to v4, they seem to be coy: under the Platform column they just say: "Mac OS X"