Medicaid payment delays of up to six months are causing fits for supportive living centers throughout Illinois, and some owners are worried they may have to close if the situation doesn’t improve soon. Gov. Pat Quinn is working with the Illinois Finance Authority on a program that would allow private investors to “buy” up to $2 billion in outstanding Medicaid bills. The investors would be repaid by the state later — with interest — while Medicaid providers would receive quick infusions of cash.