Whenever resizing the Minecraft window, it will cause GUI issues. Either the screen will become blurry or part of the window will get cut off. Not sure if this is happening on Windows, but it is happening to me on Mac.

When closing the game, an error does pop up like this:

Client> 2013-07-07 11:24:12 [CLIENT] [SEVERE] ########## GL ERROR ##########
Client> 2013-07-07 11:24:12 [CLIENT] [SEVERE] @ Post startup
Client> 2013-07-07 11:24:12 [CLIENT] [SEVERE] 1281: Invalid value
Client> 2013-07-07 11:24:13 [CLIENT] [SEVERE] ########## GL ERROR ##########
Client> 2013-07-07 11:24:13 [CLIENT] [SEVERE] @ Pre render
Client> 2013-07-07 11:24:13 [CLIENT] [SEVERE] 1281: Invalid value
Client> 2013-07-07 11:25:12 [CLIENT] [INFO] Stopping!

Images are attached below.

Image 1 shows that when resizing the window, part of the screen will get cut off.
Image 2 shows that when resizing back to normal, it will start flickering.