I generated a MIDI file from MacBIAB 2010 to be read by Sibelius 6 (Mac) but I am getting a message that the MIDI file is corrupt when I open the file on Sibelius 6. On the other hand, the MIDI file generated from PC BIAB 2008 can be read by Sibelius 6 (Mac). What kind of MIDI file generated by MacBIAB that cannot be read by Sibelius 6?

I am using MacBIAB 2010 crossed over from PC BIAB 2008, using IMac 3.06GHz just a couple of days ago.