I think the problem is 22khz and 16khz Voices....... u can convert the 22khz to 16khz and it should work..... same thing happened on my 6260.
the easy way to try that out (if u want to), try download free voice (by PC) from tomtom.com (UK site) and put them on the voice folder in your cell phone..... it should not work.
but if u download by your cell phone direct from tomtom, it'll work.
it's not that ez to tell how to convert from 22khz to 16khz....... but u can email the voice files to me and i convert and send it back to u guys.
but need to be English Voice...... coz i don't understand others..... unless chinese.. haha!
zerozero_00@hotmail.com