Please Help Me with Audio Card Issue

My list:
Workstation: Apple Mac Pro 5,1
OS:Mac OS X Lion 10.7.2
CPU:6-Core Intel Xeon 2 X 2.66GHz
RAM:6G 1333MHz
HDD:1T
Audio Card:Avid (digidesign)Pro Tools HD3-PCIe
Audio Interface: Avid HD I/O (8 Analog input, 8 Digital input, 8 Analog output, 8 Digital output)
Driver version:Pro_Tools_HD_Driver_v90_r3_73493
Software version:Nuendo 5.5.1(32bit)
Audio Mixing Studio

Now Nuendo can not recognize all the inputs/outputs of audio card. In Device Setup/VST Audio System/ASIO Driver, I choose Digidesign HW(HD). There are only 8 inputs and 8 outputs, however the Avid HD I/O has 16 inputs and 16 outputs. It displays “Digidesign Input/output Stream X”. Nuendo recognize Analog inputs and outputs only.

In Avid Core Audio Manager, it displays “Chanel: 8 input/8 output”. And in Audio MIDI Setup, it displays “Chanel: 8 input/8 output” too.

Please give me some advise.