Do you have Free Will turned off? Because I had the same problem, turned Free Will on again, and the keyboard shortcuts worked just fine after that. This probably works for any weird game setting you might have turned on.
Do you have HP PC or laptop? Because with HP computer you get a program, which uses this combination. So you must find this program and delete this shotrcut that it uses, or if you don't know how just uninstall this program if you dom't use it.
Or - just if you have windows Vista, you must type one more (but I don't know anymore which) - so you have 4 typing together for this cheat.
And first- where do I find hp health check?
I tried all the things you said, but it still doesnt work ( I didnt try with hp health check because I couldnt find it! ) It keeps taking photos and so on... can anyone please help???