Your thumbs are way too fat. They weigh in for about 40 KB and should have at most 10. No visible difference to the original. If you like to see the proof, I'll send them attached. Oh, I see, you only have the blowup and reduce that to a thumb.
Thumbs are to save space and speed things up.
Saved your page, cranked up the html editor. That's a thumb. It only takes seconds if you know what to do. It's free for 30 days and they add another 30. The biggest problem people seem to have is saving the jpg twice.