You misreading things, the Asus P5-QPL family of motherboards have ..
1 x PCIe x16
1 x PCIe x1
Both slots support PCIe 1.1 Architecture.
Your GT430 is correct and says it is connected at the highest speed possible, so don't worry, everything is ok, that card isn't designed to be a screaming gamer, but more for casual gaming and good move playback, while keeping heat and costs low.