How do I handle two jury summons with a few months of each other?

My husband received two jury summons within a few months of each other. One for one court downtown and the other for a nearby city. Juror ID numbers are different, but names are the same. He registered for the first, was on standby, called daily, and was let go by telephone. The other he ignored because of the first summons. He just received a postcard stating he will be fined if he doesn't respond to the second summons. What is the best way to address this because I understood once you serve (able to serve on a jury, just waiting to be told to show up, and then dismissed) you're done for a year. What bothers me the most is the different juror ID numbers, but same name.