QuickForm - uploading file larger than php.ini POST size blanks out form

Greetings; here is the issue I am experiencing. Let's say that my form field allows a file of 5M to be uploaded. My php.ini has post_max_size = 8M. If the user submits a file over 5M but under 8M, the form returns an error message and the rest of the form fields remain filled with the posted data. If the user submits a file on my form that is over 8M, the form renders but displays no error message. The rest of the form fields are now empty as if the form was being hit for the first time or never posted. The php log file records "PHP Warning: POST Content-Length of 17635382 bytes exceeds the limit of 8388608 bytes in Unknown on line 0"; no surprise there. But why is the page acting like the form was never submitted? Is this a limitation of php (file upload to large; don't act like form was submitted), or is this something that can be coded around? Thanks. - luis