MD11 flight crew reported confusion over the inspection requirements of an MEL item concerning an aft main fuel tank boost pump.

Narrative

The aircraft had an MEL procedure for the #2 fuel tank aft pump. The requirement for the MEL was for the aircraft to be fueled for an additional 2000 LBS of fuel above the amount required for the flight. In addition the flight could not be flown more than 120 minutes or 900NM from a suitable airport. The final requirement for the MEL was that the mechanic inspects the fuel system after each refueling. When we arrived; I wrote up the primary observer's seat. I informed the mechanic of my logbook write up and my crew and I took a 2.5 hour break to wait departure time. When we arrived back at the aircraft; I was concerned about the requirements of the MEL for the fuel system and the completion of the MEL for the observer's seat. I contacted my dispatcher. He investigated and found that there would be suitable runways within the prescribed distance along our route of flight. While on the phone with him; I got an update of the weather. The mechanic had finished the logbook sign off for the observer's seat and deferred the seat. We closed up and departed. The next day I returned to my hotel room and found a message from the company saying there was a logbook issue on the flight the previous day and that I should call. After several attempts I finally made contact. Talking with him and working with a maintenance operational person; there was a possible determination that there needed to be an inspection of the fuel system every 10 days and that had not been done. Further discussion led us to question whether the mechanics involved understood the date that the inspection was required. The operations man said that he would continue to investigate. Later I received a voice mail from operations stating that the uncompleted; recurring inspection that was in question was not a 7 day or 10 day interval inspection; but the inspection required by the mechanic after every refueling. I think that my discussions with the dispatcher concerning the operational portion of the MEL in question and the mechanic's work on the observer's seat distracted us on the last requirement of the fuel system MEL.