I have similar situation. I can`t restart X without rebooting, either

How much memory do you have? How much is free when your at the point you need to restart X?

I may have been wrong in my last post? It might have been Firefox that froze up, I was downloading a rather large file both times. I upped my system from 768MB to 2GB of ram today so I'll see if that helps.

One thing I was noticing after upgrading to -current was after dropping out of X free showed only 390MB free. Maybe that wasn't enough to restart X and KDE (usually got a black screen with mouse pointer).

I have only 512MB but that`s enough for XFCE. I have another idenctical machine with Slackware 12.1 and it works perfect. Graphic is stable on older xorg and intel driver. Furthermore I`ve been testing intensively other distros and they also have problems with graphics on my box.

Here, I have these symptoms that occur quite randomly:

1. When I log in using KDM sometimes KDM crashes and I`m bounced to KDM login window again.

2. Sometimes I get black screen after login and only reboot helps.

3. When I start another X session and I`m switching between them with Ctrl+Alt+F7(F8) sometimes I get black screen and only reboot helps.

4. When I log in and use computer without changing X session it works mostly stable.

I guess my previous post was wishful thinking. I installed GoogleEarth via SlackBuild and had a freeze up that I was able to <Ctrl><Alt><BS> out of but a reboot was needed to get X back. I wonder if there's any hope for this 82845 chipset.

Anyway, I'm back to xorg.conf, vesa and reliability until I have time to try the other Intel drivers (2.9.0 ....)

UPDATE:

On Feb 2 I upgraded to Slackware-current and yesterday I upgraded to libdrm-2.4.17 and xf86-video-intel-2.10.0. I also added append = "i915.modeset=1" to my lilo.conf. X and KDE seem to be working much better except for:

When I leave X and go back to a terminal instead of getting straight text I'm getting graphical text (framebuffer??)
but when I start my computer I get normal text?

Should I switch to a framebuffer for start up so everything matches? Personal choice I guess.

I was able to freeze thing once by testing a few of the GL screensavers in succession, but that's not normal use.