F5 Big IP LTM & SharePoint 2010 Do Not Fragment Bit

I am curious if anyone has run into an issue in which a Windows 7 machine that communicates directly with a SharePoint 2010 web front end does not receive a DF bit from that Web Server though when that same Windows 7 client communicates with a virtual server on the Big IP, the SharePoint server responds with a DF bit.

 

This Windows 7 client sits on a perimeter network and establishes a three way hand shake just fine but when the Web Server tries to send any type of payload the DF bit gets set and the client never responds. A successful three way hand shake is also made when communicating directly with the SharePoint FE though when the web server begins to send a payload that is larger than the MTU, the DF bit is removed.

 

The Big IP is running 11.6 HF1.