Can I prevent onloading?

[Acryl]

Hi

I have problem because I have only 512 Kb/s upload. All pictures are (or seem to be) loaded when the thumbnail is shown in site. When you click on the medium size picture, the full size picture is shown immediately, so it has to been loaded before to cache.  I have normal pic size 400x300 and mostly the original image is 1600x1200 and that picture slows down whole site functionally.

Am I wrong, or can I do something about it?

edit: Hmm, me stupid, localhost is of course quite fast... Cache also showd me that only big pictures that are chosen is downloaded

Sorry