I installed kernel 2.6.39-994.201104200727 from http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-next-proposed/. This solves the blank screen issue when an external monitor is connected (ThinkPad T410s with Natty).
I installed kernel 2.6.39- 994.20110420072 7 from http:// kernel. ubuntu. com/~kernel- ppa/mainline/ drm-intel- next-proposed/. This solves the blank screen issue when an external monitor is connected (ThinkPad T410s with Natty).