Does the note just go anywhere in wierd places leaving crazy rests say a dotted 64th or even stranger? I create/drag notes around so I don't have to keep changing the note value. One time the snap broke and it would not snap properly.
I had a problem like this in X1. I fixed it by uninstalling X1 and re-installing it. Note, there is a way to uninstall it with instructions here on the forum somewhere.