Solved: the issues was caused by VirtualBox (with vrdp active). Solution for now - do not have virtual machine autostart at boot. Thanks <div class="gmail_quote">On 19 April 2010 16:22, Felix Oxley <<a href="mailto:felix@oxley.org">felix@oxley.org</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">Hi, I suffered a brief (10 second) power cut leading to a hard power off. Since that time, when I log in to Gnome, my system is very slow to respond. System monitor shows constant CPU activity even when I am doing nothing. top command reports that Xorg is using ~90% of CPU. I have forced an fsck on all drives and rebooted multiple times to no effect. Since the fault developed I have upgraded to Ubuntu 10.04 but the problem persists. Xorg version is 7.5. Graphics card RV710 [Radeon HD 4350] Currently using Linux driver (afaict - fglrx is showing up in lsmod), but problem occurs with either the proprietary or inbuilt driver. Can anyone please suggest steps to troubleshoot/resolve? Thanks System details: Originally Ubuntu 9.10 Linux molly 2.6.31-20-generic #58-Ubuntu SMP Fri Mar 12 04:38:19 UTC 2010 x86_64 GNU/Linux now: Ubuntu 10.04 Linux molly 2.6.32-21-generic #32-Ubuntu SMP Fri Apr 16 08:09:38 UTC 2010 x86_64 GNU/Linux Quad core Opteron 1352 2.1GHz 4GB RAM Separate partitions for / /home /boot /tmp plenty of disk space. </blockquote></div>