I run an up-to-date Jaunty system. I've experienced this problem since about February when I moved from hardy to jaunty.
Not sure where this bug is hiding. I'm using Gnome, but I have quite a bit of trouble with keyboard entry where I suspect scim is the culprit. Help in pinpointing the issue greatly appreciated.
I have four workspaces. It happens at times (not always, but frequently enough to be annoying, about 25% of the time, I'd say) that when I use Ctrl+1 to switch to the first workspace for example, that a string of "11111111111111" is continually input into any text field in the active window on that workspace. It's almost as if the 1 key was stuck (which is not the case). When I go to Ctrl+2, it will be "2222222222". Hitting Esc will usually end any further input. But almost any key I hit (such as backspace for deletion) will output another "1" or "2" character. The character is always the same as the workspace number that I just switched to.
If I was using VoIP at the time this happened, the partner on the other end of the line and me will hear a regularly recurring beep sound. I'd say the frequency is either once or twice per second.
"dmesg|grep kbd" right after this happened will get me "[194092.286510] atkbd.c: Spurious NAK on isa0060/serio0. Some program might be trying access hardware directly."
Although similar, I don't think I am seeing bug 124406 for the reasons I have given there.
I recompiled kernel git HEAD the other day and the problem is present there, too. If this is a kernel bug, it is not specific to Ubuntu patches and still unresolved upstream.