File upload associated with wrong entry

I have a form where along with other info, a user can submit a file. The file is then put in the proper gravity forms upload folder. Here's the problem:

On several occasions, the associated image has the correct file name, but the image itself belongs to another entry. Usually, the entry it belongs to is lost ( no email confirmation, no entry).

I'm having trouble tracking down this problem, but it seems as though these entries collide when they are submitted at the same time. One entry goes missing, and the other has the wrong attachment.

I have turned off caching for the page with that form. I don't know if caching would cause the problem described, and I haven't had it disabled long enough to know if the problem is gone.

Anyone having any luck identifying the issue. I have a form that is requiring submissions of Word doc's for a writing competition that is ending this week and this is happening.

What is happening is that there are two entries. Only one has a file associated with the entry but it is the file for the second entry and the first entry's file is missing.
The entry that has a file associated was submitted at 11:43am and the second entry was at 11:45am.

PHP Version 5.2.17
MySQL Version 5.5.31
WordPress Version 3.5.1
Gravity Forms Version 1.7.2