Digital BW, The Print

I'm trying my first profile with a matte paper on a 4000 and WinXP 
Home and printed out my ink separation print.  I didn't change any 
of the settings in Ink Calibration Mode.  I don't have a 
densitometer so I used my loupe and found the max out point between 
85-90%.  (If I had used the naked eye I would have guessed that the 
max out point was at 45%) With the loupe I could see very gradual 
increases in coverage up to about 85% that I couldn't see by simple 
visual inspection under my desklamp.  I set the slider to 85% and 
printed again.  After the print dried I scanned it and got readings 
of L at 2 all the way from 40% to 100% on K.  The L reading on LK at 
100% was 18 and the nearest K reading was 20 at 15%.  I also tried 
setting the slider at 45% and got L readings of the K strip that 
were in single digits from 100% down to 40%.   

This seemed so absurd that I printed a grayscale 21 step wedge in 
QTR and then the same in PS with black only.  Both of these appeared 
to have a normal white to black range.  The BO print appeared to max 
out at about 85%.  The QTR print had good separation at least to the 
95% step.  This tells me that my printer is not radically off.  What
could be causing the strange Ink Calibration Mode readings?