That is pretty strange.. make sure the ringtones are m4r files example: ringtone.m4r. Maybe somehow during the homesharing transfer, itunes converted the tones to mp3?
You can do this: since the song/tone is now in your itunes, right-click it and choose create AAC version. Now you have the same song in a different format. Locate that file in your file browser and rename the extension (m4a) to (m4r). Then drag it back to your itunes and it should appear in the ringtones section.
Another way is to download them again with your desktop, but I'm sure you figured that one out already =).