Cannot get custom ringtones to restore since update?

I have an iPhone 4s and am running the 6.1.1. software on it. I am a PC user and have the latest iTunes 11 update as well. When I did the last software update on my phone, I cannot remember the exact error code, but it was something along the lines of “install failed due to file corruption”? Anyway, I did a restore on the phone. Everything restored just fine EXCEPT my custom ring tones? I can see them in my iTunes folder, they are still on my iPod, but I cannot get them to restore to the phone? I have tried to drag and drop manually, plugged my phone in and attempted a sync countless time with no success.

Does anyone have a solution to this? I am missing my ringtones and would like to get them back on.

Thanks in advance for the help.