See info:
http://chaldee1.gotadsl.co.uk/~richa...ead.php?t=1908

For catalyst use - Macs have to run in 32bit mode not 64bit


2010 MacPros 5,1 Boot in to 64Bit
New 2010 MacPros 5,1 boot in to 64bit mode.
3rd party drivers used with catalyst are not compatible with 64bit mode-
Active Silicon Drivers and other video digitisers are only 32bit.

SOLUTION:
MacPro need to boot in 32bit mode.
To select the 32-bit kernel for the current startup disk, use the following command in Terminal:

sudo systemsetup -setkernelbootarchitecture i386

This will sets the Mac to boot in to 32bit mode permanently
(an alternative command is available to boot in to 64bit mode)

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