Hint HB6 / KMC4400R

Just to close this issue off...

I eventually abandoned the Foxconn motherboard as it was clearly at fault, either because of the ITE 8893 bridge, BIOS, or both, and am now using an HP 8300 CMT (Q77 chipset, 3 PCI slots, no 3rd party bridge)

The KMC4400R card works as advertised (I amended the Linux TV wiki with some additional findings)
I posted the dmesg log to
https://bugzilla.kernel.org/show_bug.cgi?id=110851 FYI

Thanks for your help
Richard