Datacolor User to User Support Group.

Hi...
       I picked up my PFP v2.0 about a week ago. I just finished 
making a profile using my HP 9180 and Hahnemuhl Fineart Rag Paper. The 
colour accuracy and balance are bang on when compared to my monitor 
(calibrated twice using the included Spyder2), but the prints (printed 
through Qimage) are slightly darker when compared to the monitor -the 
equivilent of about 1/2 an f stop. Now I know I can make a brightness 
adjustment when building the PFP profile, but I was wondering if other 
8190 users making profiles for this paper are experiencing the same 
thing?
If I do use the profile building brightness adjustment does anyone 
know how much additional brightness would be equivelent to 1/2 f stop?
Thanks in advance for your help.

Regards,
Mark