Please note that the following shortcuts are KDE global shortcuts:
ALT-F1, ALT-F2, ALT-F5, ALT-F9

This means that in order for Krusader to use them, you must
first disable them in KDE's global shortcut panel. 
To do so, open KDE's Control Center, open "Keyboard Shortcuts"
and in the "Global Shortcuts" tab, disable the mentioned shortcuts.