Fuse problems

Ok like a moth ago I had some car trouble. I down shifted from low 3rd rpm to 2nd and lost power and stalled. I later figured out it was a fuse problem. I was told it was an engine control fuse. Replaced it and just yesterday I was getting up there in revs (5500 to 6000) and I went to shift from 1st to second and it did the same thing. Replaced the fuse and it was fine. What would cause this to keep happening??? Its a 7.5 amp fuse under the hood. I was told ot was an "engine control" fuse. I didnt replace it either time (was at work and my dad did it). I really dont want to replace the fuse everytime the revs get high wanting to autocross and all. Any help would be way cool of you guys.