System specs: intel P4 HT, RAM 1GB, graphics card: ASUS AGP N6600GT 128MB.
OS: Debian lenny/sid -> kernel 2.6.22.1-686 SMP (original, ie: not customized), x-server 1.3.0 using nv driver (nvidia's one not even installed).
Desktop: KDE 3.5.7

When browsing some sites using konqueror (only) the whole kde and xorg system goes down - always. After a couple of seconds I'm back to kdm login screen. Some of these sites are www.otenet.gr, www.et.gr and www.plaisio.gr.

Nothing really strange to my eyes in Xorg.0.log 
 
 The only (WW) are these: 
 
 (WW) The directory "/usr/share/fonts/X11/cyrillic" does not exist. 
 Entry deleted from font path. 
 
 (II) Loading sub module "int10" 
 (II) LoadModule: "int10" 
 (II) Loading /usr/lib/xorg/modules//libint10.so 
 (II) Module int10: vendor="X.Org Foundation" 
 compiled for 1.3.0, module version = 1.0.0 
 ABI class: X.Org Video Driver, version 1.2 
 (II) NV(0): Initializing int10 
 (WW) NV(0): Bad V_BIOS checksum (I've reflashed my video bios twice.Didn't help) 
 (II) NV(0): Primary V_BIOS segment is: 0xc000 
 (--) NV(0): Chipset: "GeForce 6600 GT" 
 (**) NV(0): Depth 24, (--) framebuffer bpp 32 
 (==) NV(0): RGB weight 888 
 (==) NV(0): Default visual is TrueColor 
 
 FreeFontPath: FPE "/usr/share/fonts/X11/misc" refcount is 2, should be 1; fixing.


/var/log/kdm.log says:

Backtrace: 
 0: /usr/bin/X(xf86SigHandler+0x81) [0x80c8631] 
 1: [0xffffe420] 
 2: /usr/lib/xorg/modules/extensions//libGLcore.so(_mesa_Viewport+0x7d) [0xae7c34dd] 
 3: /usr/lib/xorg/modules/extensions//libglx.so [0xb7bc080d] 
 4: /usr/lib/xorg/modules/extensions//libglx.so(DoRender+0x155) [0xb7bb8595] 
 5: /usr/lib/xorg/modules/extensions//libglx.so [0xb7bb862c] 
 6: /usr/lib/xorg/modules/extensions//libglx.so [0xb7bbca7c] 
 7: /usr/bin/X [0x8154a3e] 
 8: /usr/bin/X(Dispatch+0x19f) [0x808ed3f] 
 9: /usr/bin/X(main+0x495) [0x8076e85] 
 10: /lib/i686/cmov/libc.so.6(__libc_start_main+0xe0) [0xb7d1c050] 
 11: /usr/bin/X(FontFileCompleteXLFD+0x1ed) [0x80761c1] 
 
 Fatal server error: 
 Caught signal 11.  Server aborting 
 
 
 X Window System Version 1.3.0 
 Release Date: 19 April 2007 
 X Protocol Version 11, Revision 0, Release 1.3 
 Build Operating System: Linux Debian (xorg-server 2:1.3.0.0.dfsg-12) 
 Current Operating System: Linux hyperion 2.6.22-1-686 #1 SMP Sun Jul 29 14:37:42 UTC 2007 i686 
 Build Date: 09 August 2007 
 Before reporting problems, check http://wiki.x.org 
 to make sure that you have the latest version. 
 Module Loader present 
 Markers: (--) probed, (**) from config file, (==) default setting, 
 (++) from command line, (!!) notice, (II) informational, 
 (WW) warning, (EE) error, (NI) not implemented, (??) unknown. 
 (==) Log file: "/var/log/Xorg.0.log", Time: Mon Aug 13 20:24:14 2007 
 (==) Using config file: "/etc/X11/xorg.conf" 
 (II) Module already built-in 
 (II) Module already built-in 
 (II) Module already built-in 
 (EE) AIGLX: Screen 0 is not DRI capable