Yeah, if im right, the CV boots basically hold the grease in that enable the CV joint to keep moving, if its got a hole, or is looking like its on its way out its best to change them, a hole in the CV boot will allow the grease to escape, and no grease + CV joint = a nice day pay for a mechanic.
I'd just change them mate. Go to GSF's website, they sell CV boots for about a tenner each
