raiseerrro messages

I have a number of stored procedures that use raiseerror to report 
problems. I don't normally see those messages when executing these 
routines via the execute() method. I have seen them when there is a 
subsequent error exception raised in the python code. It would appear 
that the messages are being queued somewhere but not passed to the error 
handlers. 

A check of the mail archives shows some routines for adding custom 
error handles like I have done in the past with C language code. 
however these still don't seem to report the custom messages.

does any one know who to get these messages showing?

dave