I have created the Qt resource file, and added some icons (jpg,png) to it and saved it
In the designer, i have added a pushbutton, and changed it’s icon to one from the resources files

But when i run the application no icons appear…

This bug has been discussed here: http://qt-project.org/forums/viewthread/28815

and the solution was
"Try cleaning the project and running qmake again.Had the same problem a few days ago and it seems that changes to the ressource files were being ignored."

"more likely it is qmake and the makefiles it generates that screw up…"