When pasting some text, it often doesn't paste the most recently copied text, but something from earlier. This happens even when copying and pasting within the same application.
I'm using 15.04, but I've had this problem in 14.10 also. I've tried using other clipboard managers (glipper/clipit) and the problem persists. I've also tried installing parcellite.
According to clipit, copying text always registers but sometimes I can't paste. Usually what I need to do is button-mash Ctrl+c and then it works.
What's more sometimes it even becomes impossible to select text. The selection disappears immediately after releasing the mouse/keyboard (most often in gedit and nautlius). This might be an unrelated problem, however.
I often switch between Unity and i3wm, and I never had either of these problems in i3wm.
