Resizing KDE4 panel locks up entire system

[Josh2112]

Binary package hint: kdebase-plasma

System: Kubuntu 9.04
Relevant package versions:
  kdebase-plasma: 4:4.2.2-0ubuntu4

Moving the minimum size slider for the KDE panel hard-locks the system - no
mouse movement, and I am unable to Ctrl-Alt-F1 for a virtual terminal or
Ctrl-Alt-Del to reboot. I must power-off or hard reset.

My panel did not extend all the way to the right side of the screen (because of
a resolution change), so I tried to resize it by clicking the cashew, then
dragging the maximum size slider all the way to the right. This I did without
any trouble. But when I tried to drag the minimum-size slider which actually
moves the panel, it moved about an inch, then the mouse froze. After about 3
seconds the bottom tenth of the screen (about twice the size of the panel)
was painted black. After discovering I had no mouse or keyboard control, I
waited a minute or two to see if it would clear itself up, then did a hard reset.

This has happend 5 of 5 times I tried to resize the panel. Doesn't matter if
I drag the minimum-size slider slow or fast, it always locks up after expanding
about an inch.

I was able to expand the panel all the way to the right edge by doing More Settings ->
Maximize Panel, but the entire system freezing up is definitely a problem.