My version of Blender is 2.56a Beta, r34074, 64 bit for Linux.
I have alredy reported about this bug. And it has been "fixed":
http://projects.blender.org/tracker/?func=detail&atid=498&aid=24554&group_id=9But it still alive!
File > New, press F12 to render, then press F3 to save picture, enter name "pic1.png" and press enter.
If I press F3 again, I see the name of last saved picture and directory where it has been saved. Very well! :) But...
If I press Esc or Shift+F5 to go to 3D View, then press F12 to render again, and press F3 to save picture, then... The bug is back! :) I see blank name. Without last saved name and path.
The dead walk! Please fix this bug again. And shoot at it's head now. :)