Version:           unspecified (using KDE 4.4.4) 
OS:                Linux

In fact it's with kde 4.4.5 but I couldn't select it in menu since kde 4.4.5 is out today !
The problem is some time up and down arrow keys don't work in 'show in groups' mode.

Reproducible: Sometimes

Steps to Reproduce:
(happens almost every time, just once, I don't know why, it worked).
1) switch to "show in groups" mode
2) create a new dir foo
3) enter foo
4) create three directories aa, ab, b.
5) try to move focus with up and down arrow keys between aa and b

Actual Results:  
It does not work, focus is stuck to the initially focused dir, whatever it is, aa or b.

Expected Results:  
Focus should move between aa and b

OS: Linux (i686) release 2.6.32-22-generic
Compiler: cc