Restored my iPhone from backup, now cannot recover purchased ringtone My iPhone 4 was playing a ringtone that I had purchased from iTunes.

I updated my phone to the latest operating system, and in the process it said that it had to restore my phone from backup. 

Now:


I can still see the purchased ringtone on my local machine when I view it in iTunes on my PC
I can drag the ringtone onto my phone icon
When browsing my phone contents from my PC I can see the ringtone


But...


When I attempt to change the ringtone in the settings, my purchased ringtone does not appear!


I've gone to the iTunes store to attempt to download it directly onto my iPhone. A message box comes up "You have already purchased this ringtone. Do you wish to purchase it again?".  Err, why should I have to?!?

Does anyone have any suggestions as to what to try?
Have you tried removing it from your phone and adding it again (all via iTunes)? Can't think of anything else, and I don't think the iTunes in the cloud re-download everything for free applies to ringtones.