InfoPath crashes IE9 when using multiple person lookup field

I have a SharePoint 2010 list with several person lookup fields that need to be converted to allow specifying multiple people. I have found a major issue, where it appears that Infopath somehow corrupts the list any time a multiple person lookup field is used. This causes IE9 to crash whenever inserting a new row via the Datasheet view.

I have tried a number of things to fix this with no success.

Steps to reproduce are:

1. Create a new SharePoint list
2. Create a Person lookup field and set it to allow multiple people.
3. Use the Datasheet view to insert a new record. Success!
4. Open infopath to customize the form.
5. Make no changes and publish the InfoPath form.
6. Refresh the list and navigate to the Datasheet view, and attempt to insert a new record. IE9 Crash!

We have this on multiple computers running Windows 7 Enterprise, IE9, and fully patched. I've tried new Datasheet DLL files and other items to no success. Suggestions? This seems like a major Infopath bug.