Special Ringtone problems with Galaxy S from Sprint

[stebow]

I have assigned special ringtones to each of my family members, and after a period of time usually around 10 or more they all disappear and go back to the default ringtone. I can turn my phone off and power it back on and the special ringtones come back. I have to turn off my phone at least once a day to get these ringtones back. This is driving me crazy. Any ideas on how to stop this from happening. Thanks

[Tufftoad]

My first advice would be to update the phones software using Kies.