@Ken Jenkins this is normal, DiskAid is not a PC file browser, it's an iOS file browser.

We will be adding a Tones section in a future release, but for now you can use iTunes to import your ringtones like this:

1. Change your iTunes import settings (iTunes/Preferences/Import Settings) to use the AAC encoder
2. Drag your audio file into iTunes and right click (or command click/two finger tap) and select "Create AAC Version" (also located under the "Advanced" menu drop down)
3. Drag the created AAC file onto your desktop and delete the copy that remains in iTunes
4. Change it's file extension from .m4a to .m4r and drag it back into iTunes. It should then appear in Tones under Library
5. Sync your device to import the tone. It should appear at the top of the list in System Preferences/Sounds/Ringtone.

Hope this helps...