why?

why would my transmission pan bolt come loose? i did an oil change the other day on my 1996 dodge stratus and noticed red fluid on the pan so i checked it out. I touched one of the bolts on the pan and it was loose. All of them where loose. What could this be? i tightened them up and i checked up on them today and 5 where loose today.

anyone know?

Are the bolts actually tightening back down, or are they stripped out? I had to helicoil about eight of mine to get them to stay tightened down, but it solved the problem