This looks like a convergence issue on your monitor with the red color. I could be wrong but my monitor is doing the exact same thing in that corner but not as bad. It looks like on your monitor you can see it very well under the corner towards the center of the screen as well.
I was looking through the manual of my monitor (25k7191) and it says you could adjust the convergence by moving the magnets behind the yoke. On the manual for a wg-k7000 it shows how to adjust them but I haven't really read much into it and to see how detailed it really is in describing how to adjust the three magnets.
Anyway take a look at the youtube video link below. I think doing adjustments like in the video would help.
http://www.youtube.com/watch?v=eDuKddayX-E
OR I could be completly wrong.. lol