When in fullscreen mode, the dirt-block background when loading worlds or changing dimensions is distorted for a short time

When loading a world or changing dimension while in fullscreen mode, the background image is distorted for a split second before changing to normal.
This doesn't appear to occur in windowed mode.
I haven't attached a screenshot, as it is more difficult to take one in fullscreen mode (F2 does not work here). Hopefully you can see the problem for yourself.
Edit: The loading text is also similarly distorted, although it's harder to catch.