problem with Qt resources

I embedded some pictures in my executable file and I used them as 'background' property of some widgets stylesheet. It works well in my OS, but when I move the executable file (with relevant .dll files) into my Windows XP or my friend's OS (Windows 7), the images don't load!
any Idea?
note:

• My OS is Windows 7 (64-bit)
• Two other OS I tried and my embedded resources don't work: Windows 7 (64-bit), Windows XP (32-bit)

Do you have deployed the imageplugin alongside the application? For JPG you will need that!