buggy resize handle in gtk application in kubuntu or xubuntu natty

[exzemat]

Binary package hint: gtk2-engines

hello
in kubuntu natty, firefox 4 had ugly black handle to resize window on right buttom.
you can see it here :
http://pix.toile-libre.org/upload/original/1301475243.png

in addition, when mine cursor is over this black Handle, the cursor become black too

it's affect too some of the others applications witch use GTk.
open office : no problem (but it's no a pure gtk-application)
I installed empathy-gnome to test : same problem.

i tried to change gtk style (I have changed oxygen-gtk to QTcurve) : same problem but some differences.
with QTcurve the resize handle is not black but it is gray, and when my cursor is over this zone, the cursor is still black
like you can see here:

http://pix.toile-libre.org/upload/original/1301741778.png

I see similar problems in xubuntu natty

[Sebastien Bacher (seb128)]

thank you for your bug rreport but it's not a bug but a design decision to add those, there is an api for specific application to turn them off if required