Unreadable lines in editor after scrolling with mouse wheel

After scrolling with the mouse wheel the lines are not redrawn correctly. There are artifacts from the previous content (scroll position). After moving the cursore with the arrow keys, the line is redrawn again, but the artifacts remain. The text is more or less unreadable, depending on the scroll. The same happens when scrolling with Cmd-Arrow on the Mac.

I've attached some screenshots.