warnings

I appreciate the validation service and it has been a real help to me being a newbie. My CSS Stylesheet validated after I corrected a couple of things but I have 37 warnings. I am using a template which I altered a lot, however the warnings all have to do with code which I didn't touch. 

a few examples are: 
      79  Property -webkit-text-size-adjust is an unknown vendor extension 
      85  Property -moz-box-sizing is an unknown vendor extension 
      86  Property -webkit-box-sizing is an unknown vendor extension 
      201  Property -moz-box-sizing is an unknown vendor extension 
      202  Property -webkit-box-sizing is an unknown vendor extension 

And continues for 37 warnings. The Template maker states that it "is built on the Skel framework." Which doesn't mean much to me. I'm sure it does to some of you. 

My question, should I be concerned about these warnings or are they because it is CSS3 and new or have to do with the Skel framework?

Thanks,
Jim