IE on surface (windows 8.1) doesn't recognize mobile version

Hi,

I have an website that checks if the user is hitting it with a mobile device.  The code is pretty standard stuff that checks iPhone, android, windows, etc.  It works great on almost all mobile devices where the main site is redirected to the mobile version.  However, on a surface pro tablet using IE11 (windows 8.1) it doesn't recognize the device as a mobile device.  Now, I know people will say it's really not a mobile device but I would like it to redirect.  Further to that, if I force the mobile site to load on the tablet the touch gestures do not work.

Any ideas?

Thanks.