This just started happening on my MacBook Pro 2011 OS X 10.10.3, Whenever I select multiple items to drag and drop the selection I've chosen either changes or the items drop in a place I haven't selected. Also, when I try to highlight a sentence in a document to copy, the highlighted area starts to invert before I finish. That is to say when I start Highlighting the beginning of a sentence, half way through what I just Highlighted is now un-highlighted and the end of the sentence becomes highlighted. Any ideas? Thanks