Ishbar,
I have seen this with bad cards or bad PCI connector.
The I/O Card Parity Interrupt refers to the interrupt generated to gain control of the PCI BUS.
NMI is a Non Maskable Interrupt, pretty much an interrupt that can not be ignored or masked off by the system normally.
The error indicates something went terribly wrong when a card or device tried to do what it had to do. I would start removing “unnecessary” cards, re-testing in between. Hopefully it is a card as onboard devices access the PCI bus with interrupts also and you can’t replace them.
-Fred