I'm a n00b to Apache and XAMPP and especially mod_rewrite. I added the following lines to my httpd.conf for debugging mod_rewrite problems:
# RewriteLog "logs/rewrite.log"
# RewriteLogLevel 9
I think it would be helpful to include these in the standard XAMPP httpd.conf (commented out as above) so that n00bs like me could see quite easily how to turn on logging.