A New Version of WordPress Message….

Could anyone give me any pointers on how to remove the A New version of wordpress is available.

I’ve done a search for those strings, but not come up with anything, is it originating from an outside source?

The wordpress setup is a corporate intranet. It’s currently being used lots, however the md of the company doesn’t want me to upgrade to 2.5 (Doesn’t like the new style of the control panel) – But would like me to remove the message that is displayed….

Thank you for any help you can provide

dan