Slackware 13.37 x86_64 Radeon HD2400XT Problems.
 

Exact same problem (black screen, cursor top-left, nothing in Xorg.0.log, total freeze), under slackware 13.37 64bits, fglrx version 8.95 (catalyst 12.2), with the card RV610 [Radeon HD 2400 XT].
Found no solution so far, nor anyy hint to where to look for a solution or even knowing what the problem is.
Radeon driver works ok for me...but not for OpenArena, too slow even in window mode.

Do you have any errors in /var/log/messages ?

No, unfortunately, nothing.

Moderator response
 

Moved your post & replies to a new thread. That way you will get targeted response.
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Edit: Slackware forum should get resolutions for your problem

Have you installed the driver directly or have you told it to make a Slackware package and installed that? Sometimes it seems to give problems when you use the package approach, so if you have done that try the direct approach.
Also, have you run aticonfig --initial after the install?

I tried both. First I tried to build the Slackware package and installed it.
As it didn't work, I suppose ati makes an error in making the Slackware package, so I tried the direct approch. Same result.
In both cases, I run aticonfig --initial to build an initial xorg.conf file.

I must precise that I have two monitors connected, through a sort-of Y-cable, with two VGA connected monitors. This configuration works ok with the free radeon driver, but I got poor performance in OpenGL games.

When the screen goes blank, and the machine seems to lockup, have you tried accessing the system remotely via ssh from another machine?

I had a similar problem (also 64bit and Radeon). Somewhere on the web there is a post saying that it was related to xscreensaver and to remove it. About 3 weeks ago I removed it, and haven't had any problems since. That is not enough time for a real test but I have my fingers crossed. You might also try commenting the line
/bin/setterm -blank 15 -powersave powerdown -powerdown 60
in rc.M if the problem persists.

Also, removing xscreensaver means that your screen will only blank after 5 minutes of no use, i.e. there won't be any graphics displayed, but as long as pressing a key brings it back, that's just fine.