Problem with Easy Gallery in Joomla 1.5

I installed Easy Gallery on a Joomla 1.5 site and initially it worked beautifully. Then after I had installed / uninstalled a slideshow plugin, only one half of a selected image would appear in the lightbox (can't guarantee that this is the reason, but it was the only thing that I have changed). I've searched high and low for an answer. I really liked this plugin - did everything I wanted - and then something went awry. It may have something to do with slimbox, from what I've read. Also, strangely, the problem only occurred in Chrome and FireFox - in IE the images came up wit开发者_开发百科hout any problem.

The site is getting a lot of visits at the moment and I've had to install another gallery while trying to sort this one out.