Firstly would like to thank you for the theme Cyberchimps, and also say this may not be an issue with the theme but need to start somewhere!
I am running WordPress 3.41, latest version of the Eclipse theme and also version 1.9.3 of Nextgen gallery (all current versions as I type).
The problem I have is when in Chrome the gallery thumbs Nextgen gallery, all auto size and stretch with the browser window, however when in IE 9 or latest version of Firefox they stay the same size and then overlap each other if the browser window is reduced to a small size.
The issue can be viewed here http://www.scranney.co.uk/gallery/landscapeandnature/
Thanks in advance,