Broken keyboard layout when using Mac with Apple Wireless Keyboard to access remote GDM on Ubuntu?

[Ralph Seichter]

Hi folks,

I'm having keyboard trouble when accessing a remote GDM on an Ubunto box
from a Mac. I use an Apple Wireless Keyboard (Bluetooth) and a wireless
Mighty Mouse. The mouse works during the Gnome session, but the keyboard
is completely useless, presumably because of configuration issues on the
destination machine causing a broken keyboard layout. By the way, I use

  Xquartz -query ubuntu.machine.tld

to connect. I tried to change the Ubuntu machine's keyboard settings,
but there is no Apple Wireless Keyboard which I could select from the
various dropdown boxes.

I have not yet found a FAQ or Knowledge Base article where my problem is
mentioned, so I kindly ask for your help. All pointers are welcome.

-R