Glad to see I'm not alone but I got it ...finally. (this may be the long way but I assure you it works)
1.) Change folder option to show file extensions. (For Windows 7, it is in control panel, folder options). You want to make sure the box that says Hide extensions for known file types in UNchecked. It's important because if you are like me you were changing the file but it's not really changing unless you can see the extension.,
2.) Download your ringtones and put them somewhere where you will remember (like desktop). Make sure it is under 30 seconds in length.
3.) Open iTunes and go to Music, not tones.
4.) Use the file button on top and select add file to library. Find your file, select it and you will see that the file is there under music.
5.) Right click it and select creat AAAC Version. The new version will come up underneath as the second entry.
6.) Right click the second entry and select show in windows explorer. The entry will be highlighted and will have at the end .m4a.
7.) Right click it to rename and change .m4a to .m4r and minimize file.
8.) Go back to iTunes and right click each entry. Select delete. If you get a pop up asking to cancel, put in recycle bin or keep file - - select keep file. Sometimes I just get delete, sometimes the choice.
9.) Go back to windows explorer - the same place where you changed the file extension and that you had minimized and double click the file that you renamed to .m4r.
10.) It will automatically add itself into iTunes into the tones portion. You can click it to check or just go to next step.
11.) In iTunes, click your iPhone on the upper right and then tones which is on the bar in the middle..
12.) Right on top there is a box to check to sync tones. Click it and then click the box on the bottom right to sync to your phone.
Boom - the tone is in your phone.
I do not why it is so complicated and there must be an easier way but if you do it this way it will work.
Hope it works for you. If you find an easier way, please post.