I have this plugin activated and when I do a search on my site that uses quotes the page returned is blanked. It gets caught by the $query_string_array filter of your plugin.
For now I'm forced to comment out /*'\%22', '\%27',*/ in order to keep this plugin active and have my special search queries still working.
Also it would be helpful to render something on the page when wp_debug is set to true to help people figure out why they're page is coming back blank. Something as simple as "blocked by BBQ" would have saved me loads of time tracking down this problem.