What sort of light are you viewing your prints in? Sunlight? I ask because the 2200's inkset has slight metamerism - that is, the colors look slightly different under different light sources. I used to use a 2200, and found that B&W prints looked slightly green under sunlight and slightly magenta under incandescent light. You can't get it exactly right both ways, and I would just try for a happy medium somewhere between. Some years back when I got my 2200, I downloaded the "Grey Balancer" software that was available with the printer in Europe; it lets you tweak the color balance for B&W to however you want it. You might try googling "Grey Balancer" to see if it's still available somewhere. You can't get rid of the metamerism, however, just choose what it looks like under your preferred light source.
(Though if your prints are greenish under incandescent light too, that's not the issue, and ignore the preceding.)
Lisa