I heard that someone got a copy of a GPLed program under another license. Is this possible?
The GNU GPL does not give users permission to attach other licenses to the program. But the copyright holder for a program can release it under several different licenses in parallel. One of them may be the GNU GPL. The license that comes in your copy, assuming it was put in by the copyright holder and that you got the copy legitimately, is the license that applies to your copy.