Screen on my Dell Inspiron Duo is not working with Ubuntu 11.10, though it worked when I initially installed it (~one week ago).
Another note: the touchscreen works with Windows 7 (dual boot).
Got the same problem like you. Touchscreen was not working anymore on my Inspiron duo after update to kernel 3.xI. I found the solution here:
And reboot your system. Your touchscreen will now work again.
The problem is that the magnets both in the corners of the screen as well as the back bottom of the laptop when folded into tablet mode affect the capacitative screen.