Just noticed this, but those aren't actually thumbs. They're fullsize images loading in smaller dimensions.
samandian, you need to get yourself some sort of image editing software. There are a number of freebies out there, but I wouldn't know which to use because I'm such a photoshop freak.
A thumbnail should be a smaller version of the image, reduced in pixel dimensions and size. I like to keep my thumbs between 4-6k.