That error means that you have forced referential integrity on the users table to force an associated record to be inserted at the same time. it suggests that the UserID session you are using in the UserID column is not a valid logged in user.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.