LingQ-er picking up extra word on Firefox

I am finding that when I double click on a word to create a lingQ, very often, the lingQing software picks up both the word I want and the adjacent word. Is there a trick or a work-around that I can use to force the system to only pick up one word instead of 2? After it LingQs the second word, it is very hard to go back and make it only pick up the word I wanted. I am using Firefox 3.5.5 on Windows XP. Thanks.