Can this be fixed (at least temporarily) the Gedit way? I.e., when middle-click pasting, do NOT deselect the original text.
PS: As a curiosity, if you use the "Split window" plugin, selecting text on one panel and middle-clicking on the other will not clear the buffer (in either direction) so you can paste repeatedly, but selecting on one panel and middle-clicking on the same panel will clear the buffer (in either panel); at least on my Windows version. (Not that this discovery helps a lot to fix the bug, but at least it's a workaround in case you want to paste multiple times and really want to use middle-click.)