Internet Explorer (7-8-9) appear to remove characters from JavaScript which breaks many features-Collection of common programming errors

It’s to do with the way you’re serving .js files. In particular your modernizr, you are bringing in as follows:

(by the way, you have many JS and CSS files, it would be better if you could combine them, also your load order is a bit suspect, but that’s not the main problem)

If you simply access the URL:

http://rowbotfitness.com/wp-content/themes/businesspro/core/library/js/foundation/modernizr.foundation.js

…in Firefox, then look at the error that pops up in your Firebug console, you’ll see the error that is causing you grief in IE:

The character encoding of the plain text document was not declared. The document will render with garbled text in some browser configurations if the document contains characters from outside the US-ASCII range. The character encoding of the file needs to be declared in the transfer protocol or file needs to use a byte order mark as an encoding signature.

Not sure what is generating that JS file for you (with the ?ver=3.4.2) but you’d be better off linking straight to a JS file, and then setting up the correct MIME type in your webserver software. See here for a discussion on StackOverflow about that:

Javascript MIME Type