I can confirm this is still happening on Jaunty. Seems to happen most often under heavy network usage, such as VNC or connecting to Windows Terminal Server.
~$ uname -a
Linux jeff-desktop 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009 i686 GNU/Linux
I can confirm this is still happening on Jaunty. Seems to happen most often under heavy network usage, such as VNC or connecting to Windows Terminal Server.
~$ uname -a
Linux jeff-desktop 2.6.28-11-generic #42-Ubuntu SMP Fri Apr 17 01:57:59 UTC 2009 i686 GNU/Linux