iTunes 7.4.1 ringtones re-rename workaround discovered

So last night iTunes 7.4.1 came out which, among other things, blocked off the custom ringtone renaming method, which allowed users to add their own ringtones to their iPhone without buying them on iTunes. Well, as posters in our own comments have already discovered, it's back, and here's how to do it:

First, follow the steps of the original method

• Create your ringtone, save it as an AAC file.

• Rename the m4a extension to m4r.

• Double-click to play in iTunes.

Now, if you're upgraded to 7.4.1

• Go back and re-rename that m4r file back to m4a. That's it.

• Plug in your iPhone and that ringtone will be added to your syncable ringtones list -- and it won't pop up the error from before.

• Play your ringtones constantly for the next 10 hours until 7.4.2 comes out.

[Thanks, Engadget commenters! More here.]