Asus Xonar DX Switches OFF Randomly

Windows 7 Professional x64
Asus Sonar DX
Gigabyte X58A-UD5
Corsair HX Series 850W Modular Power Supply
Intel Core i7 950 3.06Ghz
MSI GTX 460 Cyclone Overclocked Edition 1GB SLI
G.Skill Ripjaw 6GB (3x2GB) DDR3 1600MHz 8-8-8-24

The card is inserted in the second PCI Express x1 slot:



The absolutely annoying problem is that the card stops working randomly. The usual relay switch sound can be heard (the click) and then only a restart can turn it on:

The clicks are not directly related to the power supply; they come from the relays that are used to disconnect the card from its outputs jacks to prevent pops in the speakers when powering on the computer. (There are also relays for switching to the front panel and for switching between the line-in and mic-in functions, but they sound of those is probably masked by your mouse's clicking.)

I tested the card on another machine, where it was working just fine, but when I moved it back to my machine 15 seconds after I played online radio it switched off

The computer is not even under heavy load, so it doesn't matter if I play heavy games or just browse the internet.

The floppy cable is properly connected and the power supply is more than powerful to feed it.

The weirdest part is that this same card worked just fine for like a full year and during that time no hardware changes have been made. It just started switching off like 2 weeks ago for no apparent reason.

Does everything look fine here? - Ubuntu Pastebin
Could it be an IRQ problem/conflict?

I'm helpless Any ideas what to test/do in order to establish what the problem is?

I've read them all.
I spent hours yesterday testing it on different PCIE slot, with different cables and different scenarios and couldn't make it work properly.

I am not a tester, so I will just return it as faulty. Don't want to waste any more time.
I made a simple 320kbps mp3 simultaneous audio test between board audio and the Xonar = couldn't hear a difference, so I'll just stick with the built-in audio.