Disabling clicks on a webpage should be easy: put a div in front of it with a fixed position which should get all clicks. With IE that is not easy because a completely transparent element will forward clicks to the underlying element. Some solutions I found:
Alpha filter with background
Adding these CSS properties (IE8 and later):
The idea is that the element is not a transparent (it has a background) but the filters will still render it with no opacity. In IE8 this will result in the underlying elements not being printed if printing is required.
Using transparent background PNG
This works nicely in IE8 and IE9.