There seems to be a problem with action buttons and differen versions of designers.
See:http://www.notesninjas.com/A555F9/nn.nsf/ByAlias/ActionButtons
There is also an issue with changing notes 6.03 shared action buttons with an notes 7 designer.
The buttons don;t update with a design refresh.
One way around this is to delete the shared buttons from the forms.
Update the shared Action button code etc
Then re-add the shared action.
Pain , but a workaround.
You could always just use a notes 6.03 design client....