matrox g55o millenium

Iam currently using a matrox g550 graphics card on my machine but every time
I install the software after restart my tft screen gets no signal at all and
restarting is very slow.
In safe mode I have to shut off the card to get system to work normal again.
The card is a AGP card on a ASUS A7M266 mobo.
I used the older but alsom the newest drivers downloaded from matrox.com but
it didn`t make any difference.
Can anybody give me a clue cause I am out of answers.

Thx.