Problem Images in post not showing up as Thumbnail on Home Page

I seem to having an issue after I switched my post format to show the thumbnail on the left (prior it has juust been standard.)

The image that get inserted into the post won't show up as the thumbnail on the Home Page, it just shows nothing at all. What is strange though, is that if a 2nd image is posted, then that iamge shows as the thumbnail on the home page.

For examples head on over to www.androiddoes.net and you will see several posts with no thumbnail but when you click on the article, the image is there.

Any Ideas? I'm praying that it is just something very small that I have overlooked.

Steve

I tried both of the thumbnail regenerator and still the same issue. For lots of my images I use photobucket and provide a direct link to the image when posting, so the image is not actually uploaded. It' s strange because even when using the direct link for the image, the 2nd image shows up as a thumbnail, just not the first, if that make sense.

I currently use photobucket, but have started to host images on the site, and this has enabled the thumbnail to populate as planned. Easy fix there, thanks Kevin!