RUNFOR error message

I have a form created in forms v3 (it calls another form also v3) when I am in Forms v3 I can generate and execute it with no problem. When I try to use it from the command line using runform I get the message

Form was created by an old version of IAG. Regenerate form or relink IAG.

What is going wrong ?? What does it mean relink IAG ??

Please HELP !!!!!

Thanks

-- 

*********************************************************


*  Tim Armitage                                         *

*  Software developer  -  University of Cambridge (UK)  *

*                                                       *

*  Voice - +44 223 330595                               *

*  Fax   - +44 223 330592                               *


*  Email - tim.armitage_at_mrc-bsu.cam.ac.uk               *


*********************************************************