Since sendsong in installer.app doesn't work on 1.1.3 yet, here's a program to use if you can't wait. Installation is a lil complex, so hopefully you get the instructions on there.

brief summary.

1.) Install 2.1.3 program.
2.) replace iPhoneRingToneMaker.exe with patch one
3.) reigister/enter serial number
4.) re-install 2.1.3 program again.

http://rapid$hare.com/files/94199063...2.1.3.rar.html

Replace $ with S