Ultra Mk3 making trackpad cursor jerky

[jjhp3]

Hi All

UltraLiteMk3 on a MacBookPro5,1 running 10.6.8. Has worked fine before, but haven't used the interface with the laptop recently.

Had a long talk with helpful MOTU tech fellow this afternoon. He put me through many tweaks, reloads and resets all to no avail.

Here's the symptom that seems the most mysterious - perhaps others have had the same?

Hooked up interface. Doesn't matter if Ultra is off or on, doesn't matter if FW or USB2 to laptop. The only thing that makes my trackpad cursor work again is to unplug the brink from the MOTU.

Make me think it is the power supply brink... don't have another around to test. What do you think?

Thanks in advance,

John

[jjhp3]

Still testing this and that... new results:

1) old, somethings-wrong-with-it 828MkII works OK with MBP.
2) Ultra, getting power from FW cable only, works OK with MBP.
3) Ultra with FW and getting brink power, works OK on my wife's old TiBook running 10.6.8

What does this mean? Power supply inside Ultra going bad? Brink going bad?

Thanks for any insight -

John