Hi Simon,
here are a couple of ways to hide the message bar and message alerts.
1. On the Database Tools tab, in the Show/Hide group, select or clear the
Message Bar check box.
2. Click the Microsoft Office Button , and then click Access Options.
Click Trust Center, click Trust Center Settings, and then click Message Bar.
Click the options that you want:
Show the Message Bar in all applications when document content has been
blocked
This option is selected by default so that you get Message Bar alerts
whenever potentially unsafe content has been disabled. The option is not
selected if you clicked the Disable all macros without notification option
on the Macros pane of the Trust Center. If you click Disable all macros
without notification, you won't get Message Bar alerts when macros are
disabled.
Never show information about blocked content
This option disables the Message Bar. You do not receive alerts about any
security issues, regardless of any security settings in the Trust Center.
Jeanette Cunningham MS Access MVP -- Melbourne Victoria Australia