I have already read Delete and arrow keys not working and tried what is written there. I have also tried restarting my computer. I have also searched elsewhere for answers, but I haven't found any solution.
I am using Ubuntu 12.04, and there were not problems yesterday, but for the last hour, I've had the following problem.
When I press the up or the right arrow, nothing happens. When I press the down arrow, it doesn't make anything go down, but something appears in the upper right corner of my screen:
When I press the delete key, nothing gets deleted, but something appears in the upper right corner of my screen:
The left arrow still works. Can anybody help me get my three arrow keys and delete key back?