AutoCAD 2005 not using hardware 3D acceleration

[FredBear]

Hello.

I am having an odd problem: even though I enabled hardware acceleration in
the options dialog (selecting wopengl8.hdi, the only available choice), 3D
redraws are still painfully slow (exactly same speed as without enabling
it).
It's just like AutoCAD is ignoring the setting.
My configuration is as follows : HP workstation with NVidia Quatro FX 1300
(128 MB graphics memory), AutoCAD 2005 full. I am running Windows XP SP2,
and the latest certified drivers for the video card.
I must be missing something, but what ???
Help !

Thanks in advance,

R.