Sony Vegas is skipping frames on GoPro footage

I got footage from Breck,Vail, mad river, smuggs, sugarbush, jaypeak and can edit any of it because my vegas cant process thee footage or something its really annoying,It skips like 2-5 sometimes 10 frames at a time making it impossible to edit with. on top of that it will let me render it.I dont understand why it doesn't wanna work when its a standard mp4 1080p file. any help would be greatly appreciated, thx