Bug in the preferences window

Dear colleagues,

I'm new in using a full Discovery Studio installtion on this computer, but i noticed a problem while going through Edit->Preferences->3D Window -> Lighting

Sometimes the window appears, sometimes not, but every time i go to this tab DS is stuck.

I'm ok to provide more information on this (gdb traces if needed), but i need to know if this is the right place to report this kind of bugs.

For the record, i'm using DS on Mandriva 2009 64 bits (Powerpack edition) with a nvidia card (with proprietary drivers 180.08) provided the graphical acceleration. My desktop is KDE 4.1.3 with some nice visual accelerated-effects.

Turning on and off the direct rendering does not affect the bug, so i think this is DS-specific.