I just got GT5 and a G27. If I start GT5 with the dualshock then the G27 doesn't work. And if I start the game with the G27 then the dualshock doesn't work.
Will the G27 and DS both work in GT5 at the same time? If so, how?
Yes they will. Start the game with your g27. Then turn on your ds3. Then press the ps button and select control setting. Change your ds3 to number one and off you go.