maybe you took pictures on different resolution settings, you normally get three options on a camera, low,med and high, its normally set to high as default, ie, every time you put new batteries in, it will set the picture quaility on high, which is way to big for here.
go into camera settings, and set on low as default, perfectly good enough picture quaility, and you'll normally find the load straight on, without the need to re size/photobucket etc