Just a heads up for MOTU users that haven't upgraded to Panther yet: I installed 10.3.2 two weeks ago. After the upgrade, I started experiencing some flaky behavior with the MOTU Midi Express XT USB -- about half the time, when I started Metro, it was unable to find the MIDI interface. It finally occurred to me to check the MOTU Web site for an upgraded driver, and sure enough, there was one.
I downloaded it and installed it. But afterwards, Metro couldn't find the interface at all! I looked in AMS and noticed that the icon for the XT was grayed out. What the heck? Nothing I tried would get it to work. Then, I noticed something just visible at the right edge of the window. For some reason, the driver had re-created the XT port under a new name -- it was now called "MIDI Express XT #2"!. Why it did this I don't know. It wouldn't let me delete this new icon, and changing the name of the old one didn't make any difference. What I finally had to do was do new wiring and connect all the existing MIDI devices to the new interface icon. (It let me do this despite the fact that the old connctions to the old icon still existed -- I was surprised at that.) Finally, I deleted the old grayed-out interface icon. Voila! All the old connections disappeared, and everything started working. All I had to do at that point was go into Metro and tell it to use the new name for the interface.