I use Ubuntu 12.10 but I did not really like Unity GUI because of performance issues and total inability to easily customize launcher. So I switched to Xubuntu, which is much faster BUT I have a problem, that our company messaging software is not able to detect when I lock the screen so it does not change my status to away.
I have the screen locked. I get a call and I can still answer it and see the number and contact without unlocking the screen. This might be the same for texts, not sure yet.
I did some Googling and there seems to be a setting that can change how much the screen lock blocks. I think I checked everywhere in the phone but don't see this option. It's a ZTE AWE phone with jelly bean.