DH55TC don't detect 9500GT

My 9500gt run fine on DH55TC mobo for few months untill the card failed.

I have my replacement of 9500gt yeaterday and i installed it to DH55TC mobo...the mobo does not detect the card.

DH55TC have auto function to detect PCIe cards which perfectly works with another gfx card, but not with this replaced 9500gt.

And...the replaced 9500gt also run fine with Asus p5kpl motherboard.

I have change the auto function of dh55tc in bios to Primery display driver pcie..but still on board graphic is working it cannot detect the pcie.
With another graphics card Dh55tc response perfectly.

So my DH55TC is alright and 9500 gt also alright where is the problem?

Two thing I did before instaled my replaced card
1. update bios
2. add 2gb ram with previous 2gb.

Please help..

Go back to the previous BIOS and try.

I dont know how to roll back..give some suggestion please.

^^
Did you not take a backup of the BIOS...? If not, then download the old version BIOS from the web and just flash it back.