The proposed change (line 45-ish) tries to use the jQuery plugin if the native JSON object is not found. This should be tested, but I am away from my development box at present. Could you see if it passes?
Added code to use jQuery JSON plugin if native JSON object not available
Updated for jslint; fixed confusing code; reformatted
I have updated 2.6.1 to pass jslint and refactored some confusing code. The results should be faster and minify better.