Sorry for the late answer. I had a similar ticket asking about the isotope margin issue, and I was able to implement it. I can't suggest a quick fix, this turned out way more complicated than I thought as the “gutter” parameter was not working properly so I had to implement a fix as well.
I'm attaching the pre-release version of the plugin to this reply. To install it, just deactivate and delete the current one, and install this one. Your options and data will remain in the database.
Then make sure to clear your cache if you have any, and on the <span class=”code”>Theme Options -> Isotopic Results</span> panel you can adjust the margin between the items 🙂
Please note that this is not the final version, so it may contain bugs.
Attachments:You must be logged in to view attached files.
If you like my products, don't forget to rate them on codecanyon :)