That is the way the button symbol is supposed to work.
Don't cloned the instance; create a new button from scratch if you
want it to be unique from the others.
Thanks, i will try it. Whats the difference with copying a symbol and cloning it then?
As Jim suggested, symbols work on the principal of Master-Child relationship. Any changes to the master object will broadcast the changes made to all the child symbols in the document.
Clone places a copy of the object in place. Duplicate also does a copy n paste operation with the object moving 10 px in each direction.