Gigabyte GA-73PVM-S2H and Port Multipliers

I have not been able to find comment one anywhere about this product; it would appear that the Span ad (for an unbranded and documentless thingie) claims to do things that SiliconImage, who makes the underlying distributor chip, says are not actually supported - SiI data sheet here:
http://www.siliconimage.com/docs/SiI-DS-0121-C1.pdf
However, from a cursory read of the data sheet, I believe that it should, at least (if the power/signal distributor interface is done right) show you connected drives...

A - how, physically, do you have this set-up? Did you use it as suggested, in a separate case, with it's own power supply?
B - and I guess, most important - why are you doing this? If it's because your case isn't big enough to house your drives, the money'd be better spent on a more capacious case; you'll never get actual simultaneous drive access with this, it's a 'serially activated' device; you can't RAID it; if you've used up all your on-board SATA ports and just need more, you'd be better off with an internal PCI SATA board (cheap) or a PCIe SATA RAID controller (expensive), or a server MOBO to begin with...
C - does it have a manufacturer and a manual - I couldn't access either; the reason I ask this, is I'm thinking device driver problems, and I'd like to see what's available from the maker...

SiI has, apparently, (or at least not accessible to the consumer) no device drivers available, though they do show a firmware upgrade here:
http://www.siliconimage.com/support/searchresults.aspx?...
I'd probably be hesitant to use this, though, w/o guidance from whoever provided the device drivers...

That said, assuming there are no ground loop problems between the cases' power distibution, and the install of the included s'ware seemed to go OK, start here:
-right click on 'Computer';
-select 'Properties' at the bottom;
-left click on the 'Hardware' tab;
-left click the top 'Device Manager' button;
-see if you have any devices, especially under 'disk drives' or 'storage controllers' that are showing error tags?
Post back & we'll try to go from there...
Good luck,
Bill