Bug#514975: I had the same problem.
X -configure did not solve it for me!
nor removing ~/.kde as suggested in another internet thread.
The only thing that solved it for me was downgrading xkb-data.
I did disable evdev to see if the problems were related to it, but it
Odd thing, depending on the X's configuration, the symptoms aren't
exactly the same, when i manually configured for X to use the usual
keyboard driver, instead of this "Crazy Crtl + Scroll lock" behaviour
(the first time you press a letter, it is like you had Crtl+the
letter, and the Scroll Lock led turns ON, the second time the letter
does come thru and Scroll Lock turns off), instead i got only problems
with "right side" of the keyboard, for example with arrow keys, home,
insert, del etc. (e.g: Up arrow would map to Print Screen).
I can`t recall the exact configuration, but disabling the multiple
keyboard layouts in KDE brought me to the second state too (wrong
keycodes for the right side of the keyboard).
In the end, only downgrading xkb-data solved it.
There aren`t any visible problems at Xorg.0.log at startup and while
pressing the keys.
And the normal consoles work well.