--- Operating System, Graphics card ---
MacOS X 10.7

--- Blender version with error, and version that worked ---
2.68a

--- Short description of error ---
Changing the "File" field on "Strip Input" doesn't refresh the sequencer - there isn't a feedback about change of file.

--- Steps for others to reproduce the error (preferably based on attached .blend file) ---
Open a new sequence. Add some image strip. Put the cursor above the strip. On "Strip Input", "File", change the filename to another image file. Press Enter. The preview doesn't updates the image. It can be done pressing "Refresh Sequence" button, and there is the need to press it every time a filename changes.