Hi I ran into trouble when I installed the latest version of Simple Image Gallery 2.2 for Joomla 1.5. Thumbnails render fine, but when I click on an image, they all open in new windows and not in a light-box. I tested ONLY USING core joomla templates not third party.

Unfortunately, the thing happens on your demo site www.joomlaworks.net/content/view/17/42/

I've tested your demo site on multiple PCs with - FF3/FF4, Chrome 10, IE 7/8/9. Mac FF4/FF3, Safari (latest version) and all behave the same way. I even tried an iPhone for kicks same problem. I've even had some other developer friends try it on multiple computers and everyone gets new windows not light-boxes. I think there is a bug in this new version. Can you guys please investigate and release a new version? I see other posts in this forum with people having issues with this new version too. Thanks still love the extension though.

I have the same problem on same version of joomla and simple image gallery. Any solution?

Probably a javascript conflict with another extension in your site. You may use SIG PRO plugin which has many pop up engines to choose in order to avoid such conflicts....