[bugreport] 6310 writephonebook corrupts numbers

[Len Trigg]

Using 6310 and current cvs:

Another issue I've found with writing phonebook entries is that phone
numbers often have extra digits appended to them. This seems to happen
over 50% of the time, and occurs both for the main number entry and
subentries.

I can generate some debug output if people wish.

Cheers,
        Len.