I'm curious if this was fixed in a later 5.4* series or not. Anyway, you could do a simple regexp for messages that end in a + or - like this for example:
$Message =~ s/(-|+)$//;
You'd need to modify postings.cgi and do this for new topics, replies, and edited posts.
Donate to UBBDev today to help aid in Operational, Server and Script Maintenance, and Development costs.
Please also see our parent organization VNC Web Services if you're in the need of a new UBB.threads Install or Upgrade, Site/Server Migrations, or Security and Coding Services.