Send a copy of the insert page please. Did you use Data Bridge to create it? the WebAssist insert record server behvavior will only show in the server behaviors list if you used Data Brridge to create the page and you have Data Bridge installed in Dreamweaver.
The Access point you are using is the Standard DW Insert record behavior. To access the WebAssist insert behavior, click the plus button and select:
WebAssist -> Data Assist -> Insert -> Insert Single record