I\'m sure there is an extremely simple reason that this one line isn\'t working, but it has evaded for the past week, so I\'m hoping someone else will notice my fault.
What does the SqlCommand for Update look like? I see the command but I don't see any SqlText, that's what you're missing.
You need to define what .Update does by setting .UpdateCommand property on the SqlDataAdapter
This link gives a pretty good breakdown on how to go about it: http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqldataadapter.updatecommand.aspx