Midi tempo changes when loading a song.

[flimtrick]

Hey all, i´m using Ableton live 5.0.3. The problem is that i have some midi bass for example in one song and it´s in tempo and all is fine. Then i load another song and work on that. And then i load that midi bass song again and the midi tempo is different than the tempo i worked before and everytime i have to put it in right tempo. Why it don´t save the miditempo changes??Anyone has the same problem??