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.