I search all around the internet till the 6th page of result on google with very precise search, but I can't figure how I can do that.

I'm working with last updated ubuntu 12.04 and gnome shell, and I wonder how I can REMOVE and I say remove not clear or avoid feeding but remove completly the "recent item" bookmark you can see in the standard save windows of gnome shell here's a picture (in french it's "Récemment utilisés"):

Sorry not enought point to post image to see what I talk about, just do that:
-open gedit
-type anything
-save your file
-Now that windows got a "recent item" and I want it DOWN

I cannot reward point, but I would if I could for the guy finding a solution, and a bonus point if you find a way to remove it every where it appears in gnome shell.

Thank you for time.

Antoine