Octel -- as Fletch says "Octel is German for Overtime"
-- requires dedicated message waiting ports that are realtily stupid in so far as once they think a light is on they will not try to relight a set when another message comes in. What we've found with message waiting problems is to have the user go into thier mailbox and clear out all of the new msg's and then leave them a new one which typically clears the problem.
We mostly notice a problem with lights after an ini or shutdown.
I'd also verify how many message waiting ports that you are using and on the Octel I'd use the onlne cdr to verify that all of the message waiting ports are working.
Jack