I am having the same problem. It usually occurs when my T41 wakes up from suspend to ram and network manager connects to my wireless network. When it shows the signal strength icon in the taskbar, the mouse is useless. All I managed to do is Ctrl-Alt-Backspace. I'll have to try to switch the desktop instead, next time it happens. This problem occurs intermittently.
I am having the same problem. It usually occurs when my T41 wakes up from suspend to ram and network manager connects to my wireless network. When it shows the signal strength icon in the taskbar, the mouse is useless. All I managed to do is Ctrl-Alt-Backspace. I'll have to try to switch the desktop instead, next time it happens. This problem occurs intermittently.