Recently my checking account was transferred to another institution. The purchasing institution issued us new checks and said that any check written on the old account after 60 days of transfer would not be honored and the check would be returned account closed. Well someone did not cash a check until recently and my new bank has said I am responsible. Does this make sense? Shouldn't that check be rerouted and paid? It is not stale dated until 6 months.

I am assuming that your check was returned unpaid to the payee. If so, your quickest rememdy may be to simply issue a new check drawn on your new bank. If they are attempting to charge fees or take collection action against you, I'd suggest providing them with a copy of the correspondence you received from your new bank indicating that your older checks would no longer be honored.

Agreeing with JacFSB I would also say to write a check from your new bank. Unfortunately when an account is closed, some banks only have a certain time period to completely close an account. When the account is first closed it's in a temporary closed status. So by leaving this account in a opened status for the additional 60 days, so that checks already issued can be cashed is considered a courtesy. So, if a check comes through on the account past the 60 days even if it was written prior to the expiration date, probably would be returned. This happens so the banks won't take any loses on the closed account.