I got the error again when I started computer today. The error does not happen after every boot. For what it is worth, I have executed the script given in http://xubuntu.wordpress.com/2006/09/04/howto-speed-up-shutdownreboot/ (I am planning to upgrade to Edgy.)
-- Could not initialize HAL after logging in to Xubuntu https://launchpad.net/bugs/59511 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs