is focus screen the mirror that reflects the view to the viewfinder? If it is, my 1000D has this problem also but since it doesnt affect the image produce, I care less. Its just annoying to see some spec of dust but I guess its better then possibly damaging it.
Now I'm forcing myself to get a new focus screen, but a much better one. I'm getting the EG-D, which has the focus grid.
Hmm, I thought Canon got a better one than the focus grid which is for lens w/ Aperture f/2.8 and faster? And Canon should seriously consider a auto of/on grid, it makes Canon look like ancient compared to Nikon, haha.
Btw, how is your MKII treating ya?