please help, can't download pictures

Hi everyone, I know this topic is annoying but I really need help. I'm so frustrated I can't upload any of my pictures! I searched the archives and can't find my specific problem.

I have a Mac, and my camera can take pictures at 640 x 480. I download both the high res size from my camera and the 640 x 480 size. I've gotten two pictures to download...one that I cropped using iPhoto and one that I resized and exported to desktop and uploaded from there. But no other pictures that I have will upload! Even if the res. size is 640 x 480 it says that it exceeds the 800 x 600 size limit.

Then, when I try a different picture under the same circumstances, it will just say it's "uploading..." and will sit there forever and never upload.

Has anyone experienced this problem before? 

Any help appreciated.