Leaving border select on while using the VSE results in either a garbled mess of a render, or crashing.
Blender version: 2.77a
Intel Core i5-6300HQ @ 2.30Ghz
To re-create the problem:
Press Keypad 0 to select camera view,
Press Shift-B and drag a box to select a border render
Change the 3D view to the VSE editor
Add a video
Press 12 to render a frame, or click Render Animation
The image is a garbled mess.