strange difference between live and local server responsive behaviour

I developed a subtheme for Omega 3 Drupal 7 on my localserver running on MAMP and there it worked great however once I upload to my live server some really weird issues with css appear. Basically as per attached screenshots it would seem that my margins for the same area are behaving different on live server even thou I am using the same browser. As per screenshots: on my local server there is no visible gaps between the 3 blocks in my #zone-preface area but on live server a gap appears, to make things worse when I resize the screen on live server to say tablet size screen where I had gaps between blocks I now end up having overlaps. As i said before on MAMP that area looks perfect with no gaps or overlaps... What could be causing this strange behaviour?