Comment 2 for bug 1051966

Can you give a specific example of a command that you tried, and which key combination you assigned it to ?

One likely explanation is that you have chosen a key combination that is used by the widget that has focus. Currently the focused widget is given priority which means if the widget use this shortcut, the command you have chosen won't be executed.
For example if you have chosen a simple letter as shortcut, and a list widget has the focus, the list will use the letter to begin a search. Another example with list widgets is ctrl-g, ctrl-f and others I forgot.
To fix this problem I currently hesitate between :
1) adding a check box for each shortcut to chose if the shortcut should have priority over the focused widget's shortcut
2) making ctrl/alt/super shortcuts have priority over the focused widget's shortcut