Ok, This was me. When I looked at the SQL statement to trace problem, I (sheepishly) used the wrong quotes !
Oh good - I was scratching my head trying to track that one down!
Can the single quotes be added automatically if they are not supplied?
Not really, because it's difficult to know if they are required or not, especially if custom datatypes are used, or the default is actually an expression.
Regards,. Dave.