I have the same projector, and mine is worse. Makes me wonder if these new epsons (5010) with their new panels will be any more 'robust'. Very annoying for sure. What I did was 'zoom out' enough to where the magenta hue was pushed down into the black velvet on my screen. Of course this screws up the overscan a little, but it's worth it instead of having to look at that stupid tint at the bottom.
The real problem is that this issue developed after a year and a half or so. So even if you get a refurbished projector, the problem still has the potential to arise again (and again).
You're lucky, because your screen uniformity looks better than mine (mine skews slightly to green as you move left), and my magenta line is bigger!