Uploading thumbnails and pictures into a website

[gillygirl]

I have been trying to update my website and replacing thumbnails and pictures in existing pages. Some of these have uploaded fine but most upload and then get listed as "other file" not as a .jpg file which they all are. As "other files" they won't show in the webpages. I have tried several ways of creating the tuhmbnails etc. but the same thing always happens even though I can view all these pictures in my ordinary files. I am using ordinary upload not FTP.
Anyone had similar problem?

After tearing my hair out for most of the afternoon I solved this one and it might be useful for anyone else with the same problem. The picture files all had a jpeg format but the ones that would not upload correctly had the extension in upper case (JPG). I have no idea why they had this but when I resaved them with a different name using Picassa the extension changed to lower case and they uploaded easily!
Hope this helps someone!