I've not used the gallery feature of the Image module myself, but could this be the problem: http://drupal.org/node/280764?
It seems that the sorting is done in the view that creates the gallery...
I went and had a look at my site again today to see if I could do something about it. Earlier I had tested out a view that seemed to work, though I had some problems with the styling. Today I managed to get the views set up for my pictures and the thumbnails showing more like the way I wanted. Lightbox worked right away on each exhibit so I didn't have to do anything more there.
I have several image galleries on my website (Cheamweb) and a problem I have is that the order of the pictures change. What could cause this and what do I need to do? I am using Drupal 5 with the Image Gallery module.
Cheamweb Your window into the Fraser Valley
Dave's Journey | The Macfoto Life