I encounter this regularly as well. I have attached a sample PDF.
Selecting columns or parts of columns causes neighbouring text to be
selected as well. For instance trying to select "Shortly after 1900" on
page 1, line 31 causes all kinds of other text to be selected as well.
** Attachment added
I've just attached another example (smaller file, less complicated
layout). Selecting anything in the left column causes the entire right
column to be selected and vice versa.
** Attachment added: "book review.pdf"
https://bugs.launchpad.net/ubuntu/+source/evince/+bug/594205/+attachment/16605
