My post is not about the bug/debugging session currently in progress. But could help matt geting things running again quickly while the bug is taken care of.
Instead of rewrite rules, you can use lsws's static context and use the regex you have to bind to specific scripts.
exp:^/forum/[0-9]+/ ---> /myprivate/forum.php
Of course unlike the rewrite method, using the context way requires your forum.php to parse the data out of the url.
Basically the same goal done different ways and fairly easy enough to get you off the bug on the temporary basis fairly quicky. I use the setup extensively.