Ron,
As it seems to be a problem with files from your computer try this.
Goto
http://www.tinypic.com and on the fisrt page click on the browse button, find and select the picture you want as your avatar and then click open. now click on the green upload now button.
On the next page there will be a list of four addresses under share this picture, click once in the bottom one (direct lick for layouts). This will highlight it, now hold down CTRL and press C to copy the address into the computers clipboard.
Now goto
http://www.gravatar.com , login and select manage my gravatars under the my account menu. Now click on Add new image and on the next page select "image from the internt", click in the box that comes up labled URL and then hold CTRL and press V to paste the address in the clipboard. if you now click next you should get a usable picture to crop as an avatar.