Search Task Assistant: 'create new task' drop box is off screen when task details are scrolled down

[GoogleCodeExporter]

What steps will reproduce the problem?
1. click on a long task in the STA sidebar to reveal the task details
2. scroll down the task details (hiding the task title)
3. drag a search -- the 'Drop here to create a new task' box is not shown

What is the expected output? What do you see instead?

The new task drop box should always appear at the top of the task details. 
Instead, it is not shown. We should use 'position: fixed' in the drop box's 
style.

Original issue reported on code.google.com by hafe...@gmail.com on 19 Apr 2013 at 2:12