I just upgraded from Ubuntu 12.04 to 14.04. After upgrading the terminal will sometimes, but not always, flash between the current screen and the previous screen. Here are some examples:

1. The output of an 'ls' command will flash on and off the screen.
2. But when I press enter to start a new line, sometimes--but not always--the output of ls will stop flashing and instead the newline will begin flashing.
3. Sometimes vim will start flashing between the current place and a previous place, such as right after a search.
4. This also happens when I opened just sh within a bash terminal. (I was hoping the issue was just with my .bashrc, though I haven't changed it in months and didn't have any issues in 12.04.)

This is incredibly annoying, and has made the terminal essentially unusable.Unfortunately, google-ing for a half hour hasn't shown anyone running into similar problems, either on 14.04, other versions of ubuntu,or other versions of linux.