Thanks gene ! Indeed that line in kern.log is strange and therefore interesting but It does not occurs everytime with my failure whereas that paragraph about the IRQ11 - which already provided troobles to me in previous versions of ubuntu because of my ethernet card - really is. Furthermore...I updated my system this morning with the new linux-image pkg and I may have understood something, which i'm gonna explain to you : I've been experiencing for weeks a reboot of my X server...sometimes, dont know whether it's kde, plasma or xorg but something crashes and then I'm sent back to the KDE login screen. And I think this is the same bug, and that the problem yesterday was simply that my xserver couldn't restart on its own! Because as you says, I think I just lose the interface with the system - that the system keeps working. I'll try to ssh my system from outside, I guess we will be right. Do you know if there is a mean ( a shell command ) to inspect the tty output used you by default kde uses the #7 and then you can go back to a pure console using ctrl+alt+F# because I have the impression that my all problem comes from either kde or plasma ( who knows maybe deeply from qtcore) and comes to log on a diferent tty ? As well just to check, could you remind me a shell command which permits to check the memory status of my system in real time ? I'll try as well launch a session by my own so as to get back some trace... Do you have any idea how I could better get back some traces ? Because I didn't succeed to get some when my xserver reboots...never succeed to know why !! about ath5, I don't understand your query because my wireless driver is ipw2200 with an intel card ? ----- Mail Original ----- De: "gene"