Yes I am also having this problem, for me though it doesn't always happen. Almost every flight I do that is less than 6 hours doesn't minimize, but if I try to do a 7-20 hour flight my FSX will minimize. To get it back open you only have to click on your FSX icon very fast until it re opens. It should take about 10-30 seconds of constant clicking but it works. So any other ideas about FSX randomly minimizing.