Digital BW, The Print

Hi,
I am printing BW photos under Windows XP/PS 7 on an Epson S2100/2200.
I have the usual problems with very slight magenta or cyan colour 
casts when I print with a printer resolution.

However, when using 2880 dpi I get prints which to all intents and 
purposes appear to be as near to neutral as one could wish.

Am I deluding myself or is there a possible explanation for this?
Would appreciate all comments on this.

John