Problems using idrac from a mac -- can't get the function keys to control boot

Hi

I have a machine at a remote location that I manage vai idrac through a browser using the downloaded java viewer.

This used to work fine but I replace the macbook and now I can't get the function keys to work during the boot sequence.  They perform the apple designated funtion assigned to them rather than being passed through to the viewer app.  I don't know what has changed -- most likely there was some setting on the old mac book (now long forgotten) that altered the behaviour.  There is something in the keyboard preferences which changes the way the function keys work but it does not fix this one.