Jan 04, 2009 06:29 PM|andybaird|LINK
One of these fixes worked for me, and I found another one here
http://www.velocityreviews.com/forums/t362268-guid-primary-key-in-sqldatasoure-updatecommand-wont-work.html. This fix uses the conversion of the Guid (SqlServer type uniqueidentifier) to a string and back again. This worked fine for me.
However the easiest fix that worked was the removing of the Type value for Guid fields - for a non-primary field. This made inserts and updates work in my database.
Hope these help someone else,