InfoPath Dev

I have an online InfoPath form which users go and fill out on SharePoint. About 40 people use this form once a month without issue, but for one user whenever they type any numbers in whenever the select "Save" the fields blank out. All the other fields work, its just the number entry. I haven't had any other complaints of this happening.

 I can go into his form and update the numbers, I checked and his permissions are correct, and he is using the correct browser. I even deleted the form he created and started a new one and it still deleted his numbers!

 Any ideas what is going on?

I would have the user log in to another machine and try. If the issue does not happen in that other machine, then it's a machine specific issue, such as a windows update, a browser issue, etc. It will at least help narrow down the problem.