Thank you for your post.
No apologies for still using FileMaker Server 7.0.
FileMaker Server 8.5 was the first version to certify under Mac OS X 10.5. No previous versions were retested.
I don't have access to FileMaker Server 7.0, so I can't verify the error. However, since this did work with OS X 10.3, it may very well be that FileMaker Server will not work with OS X 10.5.
You can either reinstall the old OS X on that machine, or you can upgrade FileMaker Server 7.0 to the current version 10.0.
Has anyone installed and successfully running FileMaker Server 7 with OS X 10.5.x?