I'm trying to disable two AMU's, out of 4 total, in each CGMiner session.

"-d 0 -d 1 --remove-disabled" in the first session works fine.
"-d 2 -d 3 --remove-disabled" in the second session does not work.

when I run CGMiner-nogpu -n it says "failed to open, err -3"

It appears that you intend for CGMiner to be able to do this and I would like to run two sessions for two different pools.
Thanks,
Sam