Sounds like you're up against DRM protection. Just to explain briefly, DRM is used by certain phone carriers to ensure that you pay for any content you use on your phone. The phone is set to accept certain files and only if they are encrypted with DRM will they work. It's harsh I know and I can't think of anyone who likes the idea of DRM encoding. However, there are 2 possible solutions to this:
1) Upload the tone to your PC and encrypt it with DRM using some software (google is your best friend here).
2) Have your phone de-branded. This isn't simple, and will cost. There are a few topics on this forum already that deal with de-branding.
I would reccomend option one though

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