probably a dumb question, but i have to make sure:
the forms action is to post to a page named ck-confirm.php, is the name of the page the form is on?
<form action="ck-confirm.php" method="post" enctype="multipart/form-data" name="form1" id="form1">
To submit the form, are you clicking the submit button or are you hitting the keyboard enter button?
I ask because you have the trigger set to the submit button pressed, in some browsers (cough, IE, cough), the submit button is not included in the form when there is only one other element.
to help troubleshoot, turn on error reporting by adding the following code at line 1:
also, add the dfp debug info binding to the page. from the bindings panel, expand the WA Uploaded Files Global status and drag the debug info binding, post back the debug info and any errors that occur after trying the upload again.