Can employer ask me to waive right to future claims in exchange for OK on unemployment benefits

My former employer failed to pay semimonthly three times in 2008, nine times in 2009 and all four times due in 2010 before separation. I left my employer after nine years when workers were told their non-hourly salary would be cut in half and work had to be performed over three days - same amount of work, number of hours required to work was left open and not stipulated in memo given to each employee. Company subsequently denied my unemployment claim and nine weeks later wants to withdraw objection if I waive any rights to "any and all" future claims against company. I don't know of any claims I could have down the road, but this seems suspicious to me. Thoughts?