I'm running Mandriva 2010 and Kubuntu Karmic on a couple of laptops with Intel or ATI graphics. This little annoyance exists in all of them.

It happens at the KDE splash screen just before reaching the desktop.
On Intel cards, the screen blacks out for second & comes back.
On ATI cards, the screen goes white & shows some corruption (horizontal lines) for about a second, then it comes back to the splash screen.

Everything is working perfectly, just this little thing that has been bothering me for some time. This thing goes away if I disable Kwin Desktop Effects. It happens even with Compiz instead of Kwin.

Any suggestions?

Its normal and you have to ignore it.
It is a mode switch.

Yah. I understand it's a mode switch. Years ago this sorta thing used to happen whenever I start X, but these days that seems to have gone away. So what I'm saying is, when is this gonna go away? I understand what it is & I'm ok with it but it scares my mom.

Why not just explain it to her?

/.///

I've explained to her of course & assured her that it does no harm, but it still concerns her, she's using the ATI box which shows a corrupt screen for about a second. It seems to look slightly different every time too.

Thanks for that, that does help on the intel box but unfortunately doesn't help the ATI box. I guess this is something to do with the ATI driver. I was wondering if anyone knew of any settings that I might put into my xorg.conf that might help.