I have a custom message form published to the Organizational Forms
Library.  On the form is a button with the following code behind the
Click Event:

Item.To = "johnsmith@abc.com"
Item.Send

For 99% of users, clicking the button successfully sends the form to
John Smith, and closes.  I have 2 people telling me that nothing
happens when they click the button.  This behavior sounds like the form
has one-off'ed somehow, but wouldn't everyone have the same issue if
this is the case?

I stepped 1 of the users thru clearing the forms cache, then attempted
to submit the form again .. same issue.

Any ideas what might be happening here?

Thanks,
Boyd