Libreoffice 4.35 and now 5.1. What could cause copied rows to be pasted as a hovering layer element in another Calc spreadsheet - (visibly) exactly as it would happen if I had pasted my rows into Writer. Applies to all documents. I can’t even select them - all I can do is select the empty cells underneath.
Try 5.2.2.2. What’s your OS ?
32bit windows 10.
Sounds as if they were pasted as graphics or OLE object. No idea how that could happen though.