You have to ask yourself what is it that you brought to the table and why do they not need it now? They are dealing from a position of strength, because of this knowledge. you are the one that has to deal from a position of strength. What has changed. You hae some homework to do. They want you to sign away any future rights away. that means something is about to happen. I would not settle for less than 7 months full salary and expenses. You have your homework to do. Approach this as if it is a prospective client and you really want the contract. What has changed .

Good Luck but ablove all remain calm and methodical, don't panic. Like they said in Wall Street " never let them see you sweat "