Baground picture problems

I want to change my baground pictures,(and the rest of the theme ) but it won't change from display->general/explore... Can anyone help me, please?

I did search for any threads with the same content but I couldn't find anything, so please excuse me if there is already one answered...

Display>Pics Management
Advanced mode

That's how I'm trying to do it... but ti doesn't work... neither with the background nor with the buttons...

Which skin are you using? Provide the link on hitskin.com

Which skin are you using?

It's called "floral effect"...

Provide the link on hitskin.com

What do you mean?

Can you give me a link to your forum?

Give me temporary access to admin panel(if you don't mind), i will try out to see what is really happening.

It might be in greek...

Oh, i don't understand greek.

Change the background via CSS.
Add this code to CSS Stylesheet....

Code:

body {
background-image : url('BACKGROUND IMAGE URL') repeat;
}