In case anyone is interested, I figured it out. Apparently, you cannot escape a question mark in a mod_rewrite rule as note here: http://iandouglas.com/mod-rewrite-hack-in-php-for-redirecting-old-urls-with-question-marks/ So, the solution is to use a rewrite condition, as discussed here: http://forums.digitalpoint.com/showthread.php?t=16014