I took these from SOLO2.ORG, they explain avatars, any questions let me know.
Okay, so you are having problems posting avatars? Well here's the instructions.
Step 1. On any of the Forum pages click on "my profile", in order to do this you must be logged in to solo2.org
Step 2. Once on the profile page click on "View/Update Profile"
Step 3. On your profile scroll down and click on "Select a different Avatar Image"
Step 4. Insert ther URL into the text box. If you do not have an image stored on a web server somewhere, then you can use the upload file option for solo2.org. If you do that, it will provide you a URL of the image you uploaded, but you can only upload JPG GIF and PNG images. Use the URL provided in this Step.
Step 5. Click on the "Set URL" button, this will display your image in the window for Step 6.
Step 6. Once your image is displayed click the "Select This Avatar" button.
Step 7. Scroll down on your profile page and click on the "Update Profile" button.