Saving Render Overwrite

Not really sure if this is the right place to post this. if not i guess a mod/admin will move it to the appropriate place.

Just playing around with 2.5 and i decided to try a render out, i render’ed the monkey mesh (very nice render blender has its better then max) and i clicked save as at the buttom bar(new to blender i do not know the name of this bar).

Then the interface window pops up which shows which place you are going to save the image etc, i browsed to my desktop and saved it over a existing image i had.
Once i click save as near the top right of the window it saved, however it did not give me a warning that i was overwriting a file and just saved.

Is this a bug or something that is not been added yet, if its not added it would be nice to see a overwrite window pop up for me to comfirm the overwrite.

Overall i am very much enjoying blender 2.5 keep up the good work to all developers :D.