Hexagram-
I would look at the linearization curves applied to your rip settings. Also, if you could test the configurations with and without the ICC profile applied you could tell where the problem is being introduced. If the color shift is evident without the ICC then most likely your linearization curves are the cause. If not then the ICC is the next likely cause.
If you have a current version of Softrip check out the test file we ship with each install. It should be found in a folder /psfiles/ in the same drive you install Softrip. The file is named 'generaltest018eyeone.ps - this test file has an area that is very helpful in checking for neutral greys during profiling.
Also, if your service contact is current you can give me a call.
800-683-8214
Bryan