Phone selector not saved with custom form

[Adam]

I'm trying to add the display of additional phone numbers
to my custom form. I've added the 'Phone5Selector'
and 'Phone5Selected' fields and the button to choose
which numbers to display.

It works fine in that i can call up a fifth phone numer
(say Assistant), and type in a number. the number gets
saved correctly with the record

But when I open the contact again, the fact that
Assistant was selected for that field is lost (it always
defaults to 'Radio'). This isnt true of the default four
phone fields. It seems like the Phone5Selector value
isnt being saved when I save the record, although the
control is bound to that item.

Any ideas? pls reply by email. Thanks