in the gallery admin, go to the settings and set a water mark, this will force the gallery to regenerate the images.
you can remove it after it has been applied.
Your friends over here at WebAssist! These Dreamweaver extensions will assist you in building unlimited, custom websites.
These out-of-the-box solutions provide you proven, tested applications that can be up and running now. Build a store, a gallery, or a web-based email solution.