IE8.js produces error toLowerCase not supported

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Using IE9 :( set the browser mode to IE7 and Document Mode IE9 standards

What is the expected output? What do you see instead?
An error occurred showing that toLowerCase was not supported.

What version of the product are you using? On what operating system?
IE8.js on Windows 7, running IE9.

Please provide any additional information below.
I changed the following line
var b=c.toLowerCase().split(/\s*,\s*/);

to this
var b=(typeof c.toLowerCase === 'function' ? c.toLowerCase() : 
c.toString()).split(/\s*,\s*/);

Original issue reported on code.google.com by [email protected] on 27 Aug 2013 at 4:04