I just upgraded to Ubuntu 11.04 from 10.10 using direct Internet connection and now just new looking desktop (with the Launcher on the left) is shown and system hangs. Mouse cursor is moving but clicking icons and keyboard shortcuts have no effect. Maybe something went wrong during upgrade procedure. you know, It did not finished correctly; at the last seconds of installing upgrades it gave an error saying "it can not acquire lock" and exited. I just manually clicked "restart to complete upgrade" from the menu. I run the upgrade routine again but it says the system is upgraded.
No shortcut key works, (I hit win key or Alt+F2 but the result is nothing). Yes, Caps lock is working. I mean that when I press it the Caps Lock light turns on). I am sure that there is no special process that makes CPU busy, mouse cursor is moving so fast and my CPU fans are in normal mode and does not make loud noise. I boot in Recovery mode and typed the upgrade command and as I said it says that the system is already upgraded. You know, the situation is very similar to a state that you have a window in front and clicking items in the background has no result. I haven`t installed Ubuntu from wubi.