No it should not fall out. Something is wrong.
To post pics go to
Tinypic.comClick browse and select pic from your computer/phone
Under resize select message board
Click upload now and enter the anti-spam code
Copy the code for message forums and paste it here (if you include the img in the code then you do not need to use the pic link on the forum, a direct copy is enough).
Post your post and voila you have a pic that is the correct size for the forum.