I'm getting really frustrated with an issue that Ancient Dragon discovered is happening here. Anytime that the combination
% 02 (without the space) is submitted via a textbox, it's recieved by PHP $_POST array just as a space. It's like URL decoding is happening on the fly. This happens with the message editor as well as with the search box. It happens regardless of whether JQuery's AJAX function is used to do the POST, or if it's just a regular HTML-based POST request.
<edit> Forgot to mention that we use the CodeIgniter PHP framework, if that helps.