remove card
reset PRAM (Apple+Option+P+R at boot)
check running 32 bit
shudown
re-install card
try downloading the driver again from the AS website and re-install
try enabling again with a blank catalyst show

if it doesn't work - move to another slot
(no need to re-install driver)

let me know what happens... on both your macs...
does it work in another mac?

If still not working - contact Active Silicon Directly - might be a dead card?

Active Silicon phoenix Support:
phoenix.support@activesilicon.com

send them your a system profile (not catalyst system profile)
Open system profile via apple menu and about / more info - save as XML / SPX

S