Saitek multi-engine throttles glitch?

[TheArcher]

Hi,
I recently upped my 'flight deck' from twin-prop capability to quad-engine capability (i.e., I have three add-on Saitek throttle quadrants, plus the one included in the Pro Flight Yoke).  Unfortunately, of the three add-on quadrants, only two appear in my FSX controls...  The drop-down peripheral menu will show three quadrants, but when they are selected, in reality only the first two can be programmed, modified.

Is this some glitch, does anyone else have a total of 4 quadrants to share their experience?  I'm thinking it might be a power supply issue, and I may have to buy an adapter for the Yoke (mainly because I have a basic level of computer literacy).  

Any suggestions are welcome!

Thanks,

Georges