Don't test it. During the install, simply do not test it. Set the thing up as you have, make sure all the settings are correct, and then just move on. When you get to the part where it asks if you want to boot directly into a gui, say no. You can change this VERY EASILY later on, so just go with that for now. Finish up the install, boot up, and then test the graphics. If they work, edit the file /etc/inittab, there is a line in there that reads:
Edit it to read:
This will make it so that each time you boot up on each subsequent boot, the first screen you will see will be a gui login screen.