Recorded (very poorly) Robo call: actually left same message twice. Said something about US Treasury and failure to respond will result in court hearing and judgements. Sounds like an IRS scam. IRS doesn't use the phone to notify people of these sort of problems.
Called during daytime today and left rather inaudible message but they did leave a name of who they were looking for and it was not my name and I've had this phone # over 20 years. They called back a few minutes ago; two back-to-back calls (after 9:30 PM my time) and didn't leave another message.