Double clicking a word starting with a non-letter symbol selects the symbol as well, instead only selecting the word. 

"(hello)"

In the example above, if you double click on the word "hello", this should select only the word. However, it selects also the opening bracket. The final selection becomes "(hello".

Note that the issue occurs also if you click in the end of the word "hello" and use Ctrl+Shift+LeftArrow to select it to the beginning.