GP300 programming

[SBS]

I am new to hand held radios and need some help, please.  I have purchased 3 UHF GP300s and have managed to programme two of them successfully to the PMR frequencies (I am aware of the issues surrounding this) but cannot programme the third.  The model number is P94YPC00D5-- The RSS will not let me change the TX to 466 (RX is OK) and comes back with the error that it should be 403 - 433.  However, it is already programmed  from 438 on 1 through to 442.9 on 8 - which is outside of its range.  I've tried holding the shift key down but that doesn't work.

Can anyone help with this and explain why it is currently programmed outside of its apparent range.  I realise that the only solution may be to edit the mdf files but I am hoping there is an easier solution and that I may have missed something.  I have never used a hex editor before and would like to avoid this for now (at least until my son returns home - he's the computer expert).

Thanks in anticipation.

Mike

[bw18]

Did you buy a GP300 off of me yesterday on eBay Mike?!? lol 

Ben

[SBS]

That's another one!!!