Are you resizing them to the correct size? I have had issues before when using software to resize an image, and the actual size of the image once it's saved and all is just a few kilobytes more than what I thought it was going to be (or, what the software told me it was going to be). Sometimes that can put you just over the limit for size -- say, if your supposed 97kb image ends up actually being 105kb once you click "save."
What software are you currently using? How large (on average) are the images at original size?
What do you mean by returning it to the original? Are you not saving the resized photo under a new file name?
Do you have a Flickr or Photobucket account? If so you can just upload photos there, and then they put the image into several different sizes (original, large, medium, small, icon, etc.) and you can just get that image's URL (you can add photos to the gallery by URL as well as uploading from your own computer).
Using Windows gallery also. I just tried to save a copy to desktop then chose the desktop thumb for my profile pic to upload. Can anyone see Ginos face. It shows on my control panel so Im assuming it worked. If so then think this is the easy fix for all who post about resizing images. Hope it worked. Hope this helps.