I think the new firmware must be installed in order for the unit to work with the new drivers. Don't quote me on that though. It's an easy process and in case anything goes bad it can be undone. (i.e. rollback or just reinstall).
BTW if you have any questions but can't find answers in the manual best thing to do is to submit a contact form on MOTU home page. I'm sure they won't mind addressing any concerns or inquiries you may have. That's what they are there for.
Suffice it to say I never had to do that since my MOTU has been perfect in every way since day 1. I only had to update the drivers for OS X TIger, Leopard and UB compatibility. Just routine maintenance updates. Nothing major. MOTU stuff is pretty flawless.
cheers,
[This message has been edited by 3351 (edited 07-07-2008).]