Double Internet Explorer 11 icons in Fusion 5.0.4

I run a Windows 7 virtual machine via VMware Fusion 5.0.4 on a Macbook Pro Retina. Ever since upgrading to Internet Explorer 11, two dock icons appear in my OS X dock whenever I open a single instance of IE. When I close IE, one of the icons disappears, but one hangs around and you have to go into the menu to Quit and close it out.

What's causing this and is there any way to fix it?

Thanks.

R