I am a newbie on Sony Vegas and here is what my observation is:
1). With my first project, after loading the clips on project time line, once I split and removed the unwanted portions, I saw the remaining clips on the right move to left automatically. On the same lines, if I slide one clip to right, all successive clips move together.
2). Some how some keyboard key was preseed accidentally and now when I grab and move the middle clip to right, it is going "under" the successive clip.
I tried grouping by selecting all clips and press G. It is not something which I saw at the beginning.
Any thoughts or suggestions appreciated.