This is how I post pictures from my iPad.
Click “Manage Attachments”
Click “Choose File” but don’t click upload yet
Click Photo Library”
Click the funny little sliders button in the bottom corner
Click Medium, then click “Done.” This forces the resize of your picture so it will post!
Now choose your photo
Add up to four more pictures, then click “Upload”
Click “Close this window”
Add whatever text you want to include in your post, then click “Submit Reply.” Do NOT click preview!
Hope this helps somebody!