I was layed-off in the most recent downsizing, and they prorated the IC portion of my severance package. It was very fair, in my estimation.
According to a former colleague who resigned from DSI some years ago, HR, incredibly enough, is extremely helpful and willing to advise you as to the best time to submit your resignation for max positive impact for yourself. No idea if she got a prorated IC or not.
Sorry I don't have too much specific for you, but I have learned that HR at DSI is actually some very good people.
Senya Arch (admin asst), particularly, in HR, is a rockstar.
She solves problems very fast, and looks after the reps.