This is a good suggestion. It is possible to set the number of thumbnails based on screen resolution, but it requires a bit of sleight of hand. However, it is tricky to calculate how many thumbnails fit on a screen, since the size of the thumbnails is adjustable and may be any combination of portrait/landscape mode. Also, GSP is often inserted into other web sites, so I need to make the calculation based on the gallery area in the web page, not the overall screen resolution.
In the end, I may have to just have a set number of thumbnails per page.
Roger Martin
Creator and Lead Developer of Gallery Server Pro