g1smd - 7:43 pm on Feb 6, 2013 (gmt 0)
Does it return a redirect and the new URL fail to result in content, or does it fail to redirect?
The Live HTTP Headers extension for Firefox might be useful.
The = in the pattern does not need to be escaped.
Adding ( and )? round the index\.php (and adding $ to the one in the rule) is also a good idea.