Digital BW, The Print

I recently switched from PC to iMac. 

The most annoying problem has been my inability to print B&W. After 
much trial and error I finally got color prints to come out right. 
But the B&W printing continues to elude me.

Unlike the color prints, the B&W (B/O ink setting) is grainy-looking, 
not sharp…not quality.

Now, if I choose Color ink setting, the quality gets much better on 
B&W prints, but now I might have a tint/cast to the image since I 
normally convert to B&W w/ Channel Mixer and then save to gray scale.

The fact is, the B/O setting should work, but it's not. The prints 
are grainy-looking and not sharp. Almost like its set to lowest 
quality setting.

I'm not by my machine or printer right now, but I can give some of my 
basic settings.

I usually work w/ sRGB images because I send most of my color images 
to Mpix (they require sRGB). So I capture images in sRGB, and have 
default PSCS2 to sRGB/North American (something or other)2.

I work exclusively w/ Epson Heavyweight Matte papers. I calibrated my 
iMac via the simple display settings method. I really like the way 
the images look on screen. 

Printing I go to "print w/ preview" to make sure the image fits the 
paper. I can't tell you all my settings at this point, but one change 
I incorporated that made all the difference in the world was changing 
Printing Profile (?) to "Epson 1280 – Heavyweight Matte" from "sRGB - 
1966" in this "Print Preview" window. This simple change made for a 
night to day difference in the COLOR printing. 

Now, what about the B&W printing problem? 
If I can ever fix the B&W printing problem I'm considering making my 
1280 B&W only, at which time I will be looking into ink sets from MIS…
but first things first.