Ahwell about 8 hours ago I accepted some missions but fell asleep. When I awoke all of the missions were completed. Upon going through 15 faction Ips or so I noticed there were no new missions spawning.
missions will only spawn if they were completed the hour before. so either someone is doing them before you get to see them - or you have them un-completed in your database
as for the timings when you get one - look at the creation time, you may start to see a similiar pattern and x:40 isnt it