Why does 9600GT only 8x?

I have just purchase NVIDIA GeForce 9600GT 9600GT AMP version. This is the funny problem i found,In some stands that I have a PCI-E 16x slot. GPU-Z says that I had NEN PCI-E 8x slot.Does anyone know what causes this issue and how to fix it? Any help will be extremely appreciated.

http://gallery.techarena.in/data/513/146.JPG

hi,
The board has a PCIe x16 slot in construction, but only 8 lanes connected. I would say: Buy the right board, then problem will be solve. However, it is really not bothered, even with 16 lanes, that will not affect sped.