Small bug in SPAM filter...

I was looking through the SPAM filter (working on a MOD that will allow different settings per user instead of system wide) and I think I found a small bug.

In the spam check, it checks to see if the message content is the same as the last posted message.  If so, it blocks the post.  Not a bad idea, but the SQL request to get that data, just gets the last messages and doesn't filter by user or forum.  So 2 people can post the SAME message in 2 different forums and the second one will be bounced.  Exceedingly low possibility, I admit, but shouldn't we filter that by user id or something?

Thanks.