There are a ton of tags you insert and also you insert an iframe for some reason? Iframes are never ever needed anymore and are considered bad practice! If you need to load something dynamically you can use ajax.
Also if you upload a very large image the lightbox can become larger than 100% of your screen height/width.... made me remove it!
It would also be awesome if media gallerys would automatically become lightboxed! I made this change myself by modifying the wp gallery function to add a rel="lightbox" on the link tag when selecting that the images link to the image instead of a page.