Managed to create a solution
a simple apple script to be placed in the start-up items in place of catalyst...
Here are 2 versions... one silent and one talking(!)
both load catalyst after 3 seconds - although this can easily be changed by editing the script.
Note - you may need to edit the script and check that it loads the correct version of catalyst by browsing to it on your system.
Hope this helps anyone who cant solve this issue any other way
(please do test before use on an important show!!!!)
enjoy
S