The question is, what happens if i use also an GPLed lib in the same program were i don't have the copyright? Than i can't give a special permission for the GPLed lib. So if linking a program with two libs creates a derivated work of each other, than i can't do it until i have a permission form the copyright holder of the GPLed lib.
Correct, or license your program under the GPL or a GPL compatible license. For example, GNU Readline (a GPLed library) can't be used by non-free programs.