[9.04 64bit Beta] myth-setup GUI not functioning properly

[Claus]

Using AMD64 9.04 Beta build and doing a fresh backend-only install on a new machine (Intel Core 2 Quad).

When the mythtv-setup script launches then I just get some colored blocks on the screen. I seem to be able to navigate through things using the keyboard but can't see what I'm doing.

The "MythTV Setup Terminal" Window is showing a continuous stream of errors like this:

X Error: BadMatch (invalid parameter attributes) 8
  Major opcode: 62
  Minor opcode: 0
  Resource id: 0x380008
X Error: BadMatch (invalid parameter attributes) 8
  Major opcode: 62
  Minor opcode: 0
  Resource id: 0x38001c