Ramdom Bar Lines?

Hi,
I was working on a piece one night. I saved my progress and went to bed. The next morning, the software had added 3 random bars in bar 23 and had deleted all the notes in that bar. It also created a sort of 23 1/2 bar and altered the playback in that bar. I don't know if anyone has had this before, but if you think you know a way to fix it, please respond.
Thanks
P.S I had time signature changes in my piece, and so I suspect that's something to do with it.