Well, I run Mandrake8.1 nicely, everything seems to work most of the time

I wanted to change to Slack8, to give it a bit of a test, so I wiped everything on my linux partitions and went on with the slack install. Everything went pretty much ok, up until the point where I tried to configure X.
I get messages saying my card is recognised OK, but it's not picking up my screen and to send scanpci details to the developers. It's a bit of a pity, anyone got any ideas why this might happen?