I have had this happen to me when I was trying to post a pic for someone else. The pic that was sent to me was a jpg file, but the jpg was in capital letters. What I did was: after I did after the browse and before the upload, click on the file name and remove the capital JPGand replac it with lowercase jpg. this only happened to me once, but it gave me the same message and that it what I did. If you want to resize your pics, what I use is Irfanview. It works very well and gives you many other options for touching up your pics. If this doesn't work send me your pic and I will see if it will work for me and let you know what does.

The best of luck in all your hunting endeavors!!!

God Bless,
Dave