Mendeley MS Word plugin will not work on Mac

Hi, I'm using MS Word 14.1.4 with Mendeley 1.10.3 on OS X 10.6.8. I've uninstalled and re-installed the plugin several times. Mendeley opens and works fine but there is no toolbar in Word and I can't find anything to do with Mendeley anywhere in Word. I use Mendeley with my PC also and it works fine - the problem is just on my Mac. Thanks.