@countzero
You did read the initial post ? Or even just the topic-line ?
Thought so ;-)
Back to topic:
The CV64_3D comes with it's own solution to the 15kHz prob, and therefore won't work with normal FF/SD.
Other cards have a passthrough (most of the times another VGA-Style connector), and you have to mega sure that whats going in there is suitable for the monitor, no matter wether the source is a FF (built in or an card), SD, pure AGA or even a completly different computer.