Comment 5 for bug 278757

I seem to have the same problem as Alistair, so I think it is a general problem.

My system is a Dell Mini 10v running Ubuntu netbook remix 9.04, with -upgrades and -proposed and -backports repositories enabled.

I have two users, one is admin, the other is not.

Whichever user I log in first gets normal performance.
When I switch to the other user without logging out, the netbook launcher for that second user responds very sluggish so long as it has the focus. If you switch the focus away (for example by starting an application), the system becomes responsive again after a minute or two. If you switch back to the launcher, it is slow again.
When you switch back to the first user, the performance is OK again after a delay of a minute or so. (The second netbook launcher does not have focus then, of course - there might be a pattern there...)

When you open a terminal from the slow netbook launcher and start top, you see the netbook launcher using 100% CPU (or nearly 100%). After a minute or two, this changes and the system is mostly idle again. I assume this is because you switched focus away from the netbook launcher.

I checked /var/log/messages and /var/log/syslog, also both Xorg logs, without seeing anything obvious. But then I do not really know what to look for.

This bug does affect the way I would like to use my computer:
I like to have a second user for test purposes, and it is easier to switch back and forth than to have to logout and login every time, and you do not lose your open applications that way.

Also when I let someone else use the computer for a little while I could just open another session and be able to return to my own session afterwards. (Or switch back and forth with that person as needed.)

The hardware can certainly handle two open sessions at the same time; it does have 1Gbyte RAM after all, and my ancient desktop computer can handle two full-blown GNOME sessions with just as much (or little... ;-) memory.