Digital BW, The Print

Well, I think that profiles made for me by CDTobie, solved my 
problems of getting a pretty neutral b&w print using MIS color pigs.  
I highly reccommend him to anyone who has considered getting 
professional profiles done.
A new problem, I think, has emerged, and I wonder if anyone else is 
experiencing these problems.
I'm using a epson 1280, with a NMC CIS system, with MIS pigs.  It 
appears that images are ever so slightly out of register.  Upon 
extremely close examination, one edge of the print shows an extremely 
thin line of magenta.  It is about the width of a pencil line, only 
on one of the prints borders.  In the image itself, when a figure is 
surounded by sky, the edges of the figure appear to be out of 
register, giving a bit of a pixilated look.  It is a very thin line 
around the figure, but if you really eyeball it or use a loupe, it is 
definitely visible.
This was never apparent when printing with OEM dye epson carts.  I'm 
using the same paper, either LPM or Sommerset Enhanced Velvet.
Could this be happening because I'm using pigs in a machine that was 
made for dyes??  Or is this machine slightly out of calibration, and 
need to be returned to epson.  I can remove the CIS and install the 
original carts, but I never experienced this problem with the 
original carts, all borders and allignm,ent of images seemed to be 
perfect.
I ran the head cleaning, allignment, nozzle checks, etc, and 
everything appears fine in these tests, but the problem persists.
Has anyone else using this same setup, experienced anything like this?
The printer is only about 4 months old.
Thanks
David