There is a utility you can use to flash it in a mac. Perhaps that since I have a Sil 3512 chip is why I have never had any luck.The same thing would happen. You'd be advised to hook power up to it.
Mine is a $10 two port flashed PC card. So far, it's the only PC card I have flashed that went perfectly the very first time and the only one that has so far worked. Harrymatic had a post on this so I searched for a card with the exact same chip he mentioned. As it turns out, for some reason other users with a QS could not boot off the cards they flashed with the provided ROM. But for some reason it's always worked on my QS. I have never had an issue booting my QS from that card. I only had to make sure that I had the data cables in the correct ports. On my card, the boot drive has to be connected to the top port.
As to flashing it, I did it on a PC. Via Harrymatic's instructions, that's the only way you can do it.
Harrymatic saved me about $70 by doing this.
How long of SATA cables would be needed for a MDD?