Unclaimed Property Laws in the US and Acquisition liability

In the US there is significant focus by states on unclaimed property laws and regulations. These laws were based on the old escheat rules in England and can be a large source of income for the states/jurisdictions. The laws are complicated and vary in all 50 states and 4 territories (or reporting jurisdictions). These laws can create significant liabilities for companies to submit payments to any state that they have issued a payment to (employee, vendor, customer, and others). While there seems to be little guidance (so far) on the inclusion of these laws in due diligence or pre-merger investigations, it can be significant. Has anyone found themselves facing post-merger integration issues related to unclaimed property?