Mighty mouse problems( side keys problem)

Hi.
I searched in the forum but i didn't found any thread with this problem....I bought i mighty mouse wireless from ebay, i connect to the macbook and the "basic" functions work, execpt the sidekeys. I want it to open the expose - all windows, but it doesn't open nothing, i already tryied change to other funcions, like open a program, but nothing...
It could be a configuration problem or something like that?
Or maybe a problem from the keys, but the wierd thing is that in firefox, when i press the side keys the page go back to the previous one, and the seller says that the mouse worked in his macbook pro.
And a second question, does the trackball of the mouse, when pressed is other button? i tryed put the expose to open when pressed and nothing happen =/
I don't know if this has anything to do with it, but my version mac version is 10.4.9
Thank you

ps: sorry for any mistake on the english

 

Yes, i hear a noise when i press the buttons.
I try to change the preferences, but no matter what i choose, to the trackball button or the sidekeys, they don't do nothing, except on firefox i don't know why but when i press the sidekeys they change the page to the previous page.
The seller include the cd, the box and all, like if i had buy it in a real store, i install it more than one time, but nothing diferent happen.
And other thing i notice now is that the mouse is always desapiring from the
System Preferences > Keyboard & Mouse and i can't change the name or see the battery level of the mouse, it's all blanc.
Thankz

 

Just to say that the mouse works fine now. I think the problem was the usb overdrive that i installed a time ago, i unstall it now and all works fine ( side buttons, tracball button, and i can change the name and see the battery of the mouse)
Thankz anyway.

 

The mighty mouse have a cd in the box, although it works without it, but you paid for the mighty mouse, you have the right to the cd,so my advice is for you to go to the store so they can give you other.