Trouble Submitting Form

[eluser]mcrobertstd[/eluser]
I have an existing application I am trying to debug. CodeIgniter version is 1.7.2.

On submission, the form returns itself with the fields cleared. I have troubleshot the issue down to the $_POST array being cleared of data when the form validation is run.
I have verified that the $_POST array exists at the top level index.php and in the Router.php. I verified the $_POST exists right before the call_user_func_array() function call in CodeIgniter.php and is empty after that call. It is also empty once inside the controller.

Any ideas where to look for the issue? I'm new to CodeIgniter but not new to PHP.

Thanks,
mcrobertstd