Yeah, you can re-order it via the media uploader. Just click on the gallery tab and drap/drop your images to adjust the order. The documentation also covers this if you need a more in depth example.

Hi,

I have a load of images within different galleries - they are all attached to a gallery. I have since then made more pages and assigned them the menu. I now want to change some of the pictures between galleries but I can't find a way of un-attaching them in order to click the 'attach' button again. The only option I can think of is deleting them and re-uploading, but I have added descriptions and don't want to !!

I don't think there is a way around that. It's not a theme issue, it's a wordpress issue...

I see, Thanks for getting back to me.

For future, this might help...

1. NextGEN Gallery Plugin
NextGEN Gallery is a full integrated Image Gallery plugin for WordPress with a Flash slideshow option. It allows you to add image effects, custom templates for your theme. You can even move images between galleries. It also provides other useful functions like watermarking and zip upload.

But it won't help you now... I even did a google search and came to the same conclusion.. you have to re-upload :(