I own a Janome 6600 sewing machine. Did any other owner of same machine have a problem with the bobbin case? After using the scissors on the machine my bobbin case jumps out. Could it be that the bobbin case has been worn down?
i've never heard of a bobbin case wearing out but i guess anything is possible.
i would check first, though, to make sure you have it installed properly in the machine. it sounds like it might not be fully seated.
check also to make sure you haven't accidentally loaded the bobbin incorrectly.
i've done that a few times and the results are never good. LOL