Hi Ben, Ben Goren wrote:
Next, I use dispcal to create the .cal file: $ dispcal -v -y l -g 2.2 -e -H iMac\ 2007-09-13
Have you tried playing with dispcal's -k option? http://www.argyllcms.com/doc/dispcal.html#kTry with -k0 and see if that fixes your problem - it should result in RGB000 mapping to device black - normally at the expense of grey-ramp neutrality - but it sounds as though the normal behaviour down there is interacting badly with your particular hardware.
Hope this is some help, -- Alastair M. Robinson