I recorded an HD video in 720p, and i wanted to add some effects and music to it in sony vegas. Everything was going great, the effects looked nice, until i tried rendering it. After i rendered it, the video has all this lag to it, the audio however does not lag. I dont know what is causing this problem, my computer is suitable for HD viewing, and the video i edited which is in HD played fine. Could adding effects to a video cause it to lag after rendering? Please, any help would be greatly appreciated!