Does not work on any 64-bit browser.

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Download any 64-bit version/fork of Firefox. (Pale Moon, Waterfox, 
Nightly...)
2. Install IE Tab.
3. Try IE Tab on any website.

What is the expected output? What do you see instead?
The website should render in IE. Instead, I get an error screen which reads "A 
plugin is needed to display this content."

What version of the product are you using? On what operating system?
IE Tab 4.0.20130422, Windows 8.1 Pro (although this same problem will occur on 
any Windows OS, regardless of version)

Please provide any additional information below.
This add-on is only compatible with 32-bit browsers. Please create a compatible 
version for 64-bit browsers. Thank you.

Original issue reported on code.google.com by gfin...@gmail.com on 13 Dec 2013 at 11:09