Tom Tom One - celeb voices

[ding dong]

Just bought myself one of these and am trying to add some celeb voices. Having turned the WAVs into OGGs and creating the VIF/CHK files, I am finding that some of these crash the Tom Tom when tested.

Sean Connery works fine by this process, but Austin Powers goes into a loop and the device hangs and resets. Does anyone know what could be wrong (or where I can get fresh copies of these)?

Thanks