BPM changes after Bounce to Track

Hello all i am having an issue when bouncing the entire mix to one track. After the process is finished the bpm has slowed slightly causing the entire mix to be at a lower pitch. All the instruments are recorded and i am using addictive drums for the drum track. If you undo the bounce the bpm and pitch will not recover to the original   audio before the bounce. I am using sonar platinum version 23.3.0 Build 51 windows 8 and a ni komplete audio 6 interface . I was wondering if anyone has experienced this and is there any way to recover the project without recording it again.
 
                                                                             Thanks in advance
                                                                                        Wrekij
 
                           

i will check it out