all X graphics (3d and normal, nvidia, intell, probably radeon) is displaying random glitches (random bitmaps) for a moment

[LimCore]

I observed X glitches of this type for around a year now (since end 2007), as well on intell laptops, and on nvidia.

Following glitches:
random bitmap (looks like if uninitialized pixelmap / texture, most of it is black or white often, with random dots all over) is displayed:
... when showing a new element (GUI widget) in example a page in firefox (opening new tab), a page in kmail, and so on, this happens on regular 2d desktops (with no 3d effects etc)

... when showing a new 3D element (in example on default ubuntu 8.10 in KDE, click on the KDE button and the background where menu fades-in for a moment flashes to show this random pixels.

- the glitch vanishes quickly in around 0.5 second (as if it was redrawn, this time with correct pixel map)
- the glitch sometimes looks like another part of screen of some other pixmaps, but skewed (so it looks indeed like uninitialized-pixmap problem?)

I confirmed this problems on:
- older nvidia (5200?) on ubuntu 7.10 / 8.04 perhaps
- nvidia 6800 GT, ubuntu 8.04 amd64 dual core, kde, regular "2d" desktop
- intell i915, ubuntu 8.10 i386, kde, fresh install, default 3d desktop
- intell GM965/GL960 gfx (also called X3100?) intell ubuntu 8.10 amd64, kde, default Gnome desktop
- some other boxes too

I seen this in many applications, especially thunderbird, firefox, kmail, openoffice.

It is also visible when the screen is locked (kde and/or screen lock) and then user is presented with password input box (blank screensaver with one color). In this case he often sees in background not the color (or screensaver), but a random bitmap, which sometimes (1 in 10 times?) looks like the screen but skewed a bit (btw, nice security exposure)

There are glitches on Intell's - bug#285298 - but probably this is other bug.
There are glitches like bug#212155 on radeon - but probably this is other bug.