Hi,
you could try to create a different set of redundant internal by adding
$redund_inp
metric 1
to the control file and running 'ired' in define again.
For metric values from -3 to 3 are possible.
Another idea could be to go in the 'iaut' submenu and define bonds between
some more distant atoms to get a sufficient set of internals.
Cheers,
Arnim