I'd say it's an incompatibility - noting that Sonnet G4 ZIF chips 400 - 500Mhz in a MACH Carrier Card refuse to be overclocked regardless of the bus and multiplier speed set on the Carrier card itself. Perhaps the Sonnet card is trying to run at 100Mhz FSB on the 9600, or 66Mhz which isn't possible - and the Carrier card can't help you here.

JB