Nope, doesn't happen to me using version 7d. I created around 100 entries and my scroll bar was still there.
I see you're using an XP theme - try turning off support for themes in the Vegas preferences. And also try the Windows Classic theme. I have an inkling this may resolve the issue.
I recall problems with scroll bars when I uses to use XP themes.
Have you tried adding entries until you've reached the bottom of the window? Maybe something will get "unstuck" when the deep widget code recognizes the "content extends beyond window" situtation.
Well I managed to get a scroll bar when I right clicked and selected add new row as opposed to clicked on the box and choosing one. A huge chunk of the editing space is still missing as I believe you can see in the picture. if any one has any help with that I would appreciate it.
Edit: I realize it is a little but hard to see the new problem due my having fun with photoshop but it is there. The edges just stop.