I thought I'd share my experience with the PCI-424 card and Windows 8 Pro x64 RTM. See my signature for my hardware config.
The driver (v.55333, but also the previous one) causes Windows to crash during cold boot and resume from sleep with a IRQL_NOT_LESS_OR_EQUAL Blue Screen.
I'm pretty sure it's the driver. Here's what I've done:
- I found that the MOTU card shared an IRQ (#16) with the on-board ASMedia® ASM1061 controller. I updated the driver for this device, but the blue screen remained. Since there is nothing connected to this controller, I decided to DE-install the driver and disable it in the BIOS. After that I shut down the PC.
- After start-up the Blue screen with 'IRQL_NOT_LESS_OR_EQUAL' remains

- I disabled the MOTU PCI Audio driver in Device Manager and shut down the PC.
- I rebooted; no problems. No blue screen and super fast start up (!)
- I re-enabled the driver in the device manager and again shut down the PC
- After boot, again BSOD with IRQL_NOT_LESS_OR_EQUAL

So, it's the driver alright.
Also, I found that disabling the MOTU driver causes the system to boot up twice as fast compared with booting with the driver enabled. How's that possible? Does the MOTU driver uses that much resources? Anyone?
I provided this information to tech support as well. I hope they can provide a solution to this asap.
Feel free to comment on this if you like. I'm interested in more experiences like this.