Alt+R key combination/shortcut stopped working in all my programs. I thought that I will go mad, as this shortcut is quite frequently used, e.g. in FAR Manager for seeking for files, etc. Investigation revealed that the offending program was Google Chrome, or its Chrome Toolbox extension specifically – it has Boss Key configuration, and that is “eating” Alt+R system-wide. So, remapping that one to something else, e.g. to Ctrl+Alt+Shift+R, solved that issue. Google should allow to disable these shortcuts – otherwise it is really quite painful.