Space between masonry news but not masonry gallery

Hi all
About a month ago we submitted a thread about adding a 5px space between masonry news and were given this code which worked perfectly for our blog section (http://www.quercusgardens.com.au/Rhapsody/):

a.av-masonry-entry.isotope-item{
box-shadow:0px 0px 0px 5px rgba(255,255,255,1);
}

Unfortunately it’s also adding additional space to the “large gap” in the portfolio masonry gallery which is causing the images to display incorrectly. You can see here on a couple of the images there is a white space cut out on the right of the image: http://www.quercusgardens.com.au/Rhapsody/portfolio-item/bellevue-hill/

Looking for a solution that allows us to the have gap in the masonry news item but not the masonry gallery item.

Thanks in advance.
Barb