Hi Rob,
I see what you mean by "reverting back" to no margins.
It seems that the problem here is the extra CSS the caption adds. Somehow the caption you have added makes the set margins (which is 15px on the right side) to disappear.
I assume that if you leave out the captions, there is no problem. But of-course that is no solution if you want a 5px margin WITH captions included.
What you can do is the following:
In your templates folder: Joomla Root > templates/theme110/css/ find the file template.css
Download that file to your desktop.
Open this with your favorite html editor (if you have, DreamWeaver will do, if not available, take Notepad. Mind you Notepad NOT Word!!!) and add the follwoing to that file:
div.img_caption.left {
margin-top: 0;
margin-right: 5px;
}
div.img_caption.right {
margin-top: 0;
margin-left: 5px;
}
When you have done that, save your file. Before you upload and overwrite the old one, be sure to rename the original on the ftp to for instance: template.css_original
That way, should something go wrong, you can always rename to the original and revert to what it was. Make that natural behaviour before overwriting files, you can always revert that way!