You saved my day.
I've been suffering this annoyance since I bought the machine (X201) last year. Removing the action associated to the lid closure, then closing and opening it seems to fix the problem. Will see how consistent this workaround is (just tried it once).
For the lenovo engineers: it seems pretty evident there is a problem - for at least about a year now, across all your product line using intel graphics. Randomly, when resuming from hibernation or from sleep, the hotkeys for brightness stop working, and windows itself stops showing the brightness control in the "Windows Mobility Center" (pressing WindowsKey+X).
This is kind of random in the sense it may take any number of hibernate-wakeup cycles for the issue to show up, but in the long term it seems it always shows up. In my case, I never "shutdown", I always "hibernate" unless an update asks me to "reboot". Or unless the brightness control gets stuck as discussed in this thread (although now I expect not to need a reboot that often)
I always keep the machine fully updated with the official "System Update" packages - all along since I bought it.
X201
3249CTO
Intel graphics; Core i7, wifi b/g/n, bluetooth, webcam, no 3G, 9-cell battery
Win7 32-bits professional
Intel driver: 8.15.10.2401 (updated last week from Lenovo System Update - AFAIR)
128GB intel G2 SSD
BIOS 6QET66WW (1.36) 31/5/2011
RAM 3GB
No gaming or "out of the normal case" apps: just microsoft office & libre office, firefox 5, chrome, messenger, GIMP, skype etc
'been suffering this annoyance since September '10. To reproduce: keep hibernating and waking up the machine and eventually the issue will show up. Sometimes it will take 10 cycles or more before showing up, sometimes 2 cycles are enough. Normally the issue doesn't show up in the first cycle.
Hope we can get a real fix for this sometime. At least now we have something of a workaround.
wrote:
Opening and closing the lid works for me too (and I also have no action assigned to lid closure).