Tracks mixed up

I just experienced a peculiar bug that I have not seen reported before. I saved a project and closed down Cubasis. Shortly after that, I reloaded it and tracks were mixed up. Track 2 should have been the Perc Organ but was now a bass sound that I had in track 3, but the notes and effects were still what I had set for Track 2! The same between tracks 3 and 4 and so on.

I had a couple Audio tracks in there, and they played correctly but were labelled incorrectly and had the levels set from the next track too.

Has anyone else seen this kind of bug?