When I am try to use "window to desktop" shortcut as a "alt + shift + 1" kde catch the "alt + !". It is true combination actually but when I am try to use it doesn't work. I solved the bug manually edit the scheme. Interestingly only use "Alt+Shift+1" or only use "Alt+!" is not the solved bug. When there is both of them bug solved. Window to Desktop 1=Alt+Shift+1; Alt+! Window to Desktop 2=Alt+Shift+2; Alt+' Window to Desktop 3=Alt+Shift+3; Alt+^ Window to Desktop 4=Alt+Shift+4; Alt++ I use Turkish Q keyboard. ps: sorry about my poor english.
*** This bug has been marked as a duplicate of bug 394689 ***