InfoPath Dev

I figured this out. After you asked me how the file names are created, I noticed that the duplicated files have an extra space in the file name, so they are technically no duplicates after all. I looked at the properties of the files with the extra space and noticed that they are either created or edited by one particular user in the company. So ...

 I have the following problem: I submit an InfoPath form to a Sharepoint library. I allow to overwrite the form. So, when I edit the form and re-submit, the form is overwritten correctly. However, if another user reviews the form, makes a change, and re-submits, the form is added as a duplicate of the original form into the library. What can ...