How large is this file?
You can try giving more memory to PHP by entering something like this below the error_reporting line at top of pp-inc.php
Code:
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Remember you can not upload a file over 2mb on php without altering the max file upload. My thinking here if your still having an issue and its only one or two files then the file has to be too big and is being dropped or it is crapping out something when uploading.