InfoPath Dev

I watched an end user submit an InfoPath 2007 client based form after they completed filling it out. The submit button closes the form after it has been submitted via the data connection... The form closed and did not throw any errors. Initially the user received an "Access Denied" error. This was resolved by adding the domain to the list of trusted sites. Submission after adding the domain to trusted sites *appeared* to be successful. The form remained open the entire time until submission (during and after the access denied error message). The form is not in the target form library nor is it in any of the recycle bins (either the site recycle bin or the site collection recycle bin). Why would the form appear to submit correctly (not throw any errors) and then close without submitting? I believe the form is entirely lost and the user will have to refill it.

Can you reproduce the issue, or is it limited to one (or a few users)?

If limited to a user, then you probably still have a permissions issue. I guess it's possible that the submit could be failing silently (without an error message).

I would first test with other users to try and narrow down the issue. If no one at all can submit, then it could be a problem in the form rules or in the form's data connection.