SATA card/multiplier

So I have a "Syba SD-SA2PEX-2IR PCIe SATA II 2x Ports RAID Controller Card with SIL3132 Chipset" card on my nas running on a Z77 ASRock Extreme 4 motherboard. Problem is, the card doesn't always seem to be picked up by the motherboard at boot. So if I leave a drive that is part of my RAID 6 array on it, that drive will usually fall out or never initialize as part of the array, and as it is right now with my boot drive on the card, sometimes it will not boot because the card isn't' recognized right at boot and the boot drive isn't found. This is getting pretty aggravating, and I am really not sure what to do. I have no more open mobo SATA ports and need to get more without spending too much money. I have looked at some other posts around about SATA port multipliers, but what exactly do these do? They just split a SATA into two? This doesn't cause bottlenecks? And it will work if I plug two RAID disc members into it? As in they will both show up as Independent drives and be part of my RAID 6 array? If not, any other advice on a decent quality seemingly stable card? Also, I have all the open PCI and PCI-E slots you could possibly want, so that isn't an issue, just want a good card to put in it

I am not sure if I am running backport 3.2 kernel. How do I check this? And if I am, I just get a port multiplier, plug it into one of my motherboard satas and then I get more ports off of that single motherboard sata?

Also, I just found this, seems like a good option. I just don't know if it will have the same issue as my current card, which is it doesn't always get picked up by the motherboard at boot. http://www.newegg.com/Product/…aspx?Item=N82E16816124064

You are correct, I am running 2.6.32. Although I am trying to figure out if my motherboard supports port multiplication or not, if I find that it does, how do I install omv-extras and then 3.2?
Thanks