CKEditor 3.5.3 for Java - Issues with Source Mode in IE8

I am using this with JSP and Java. This editor is perfect. My only issue with it is in IE8 - It works fine until I switch to Source mode and it will not let me edit the text there. If I hit the backspace key it will go back to the previous page in my history. Not sure what is going on here. Works fine in Firefox and IE 9.

Any thoughts? Anyone else having a similar issue?