I'll preface this by saying I'm not sure greatly about rewrite and previously, I have simply "managed to get work".
This is actually the code I'm using and attempting to make work:
RewriteRule ^messagecenter/read/([^/\.]+)/?$ dispatcher.php?category=messagecenter&module=read&action=index&messageid=$1 [L]
While using the direct url
dispatcher.php?category=messagecenter&module=read&action=index&messageid=anynumber it pulls in the page effectively, however when attempting to can get on via
messagecenter/read/anynumber/ it provides me with a 404. I've similar rules in position which do work, but that one doesn't.