Since you're using photobucket as your server;
Rather than using the IMG code:
"<img src="http://i201.photobucket.com/albums/aa316/65rosessamurai/PA0_0005.jpg">"
Use the HTML code for your signature:
<a href="http://s201.photobucket.com/albums/aa316/65rosessamurai/?action=view¤t=PA0_0005.jpg" target="_blank"><img src="<a target=_blank class=ftalternatingbarlinklarge href="http://i201.photobucket.com/albums/aa316/65rosessamurai/PA0_0005.jpg"">http://i201.photobucket.com/al...ssamurai/PA0_0005.jpg"</a> border="0" alt="ChuckTshirt"></a>
According to what is described in the profile, it accepts the HTML code, so I'm sure that means it won't take the IMG code...try that and see if it fixes it.
Apparently, the body section for posting does the opposite (doesn't support the HTML code). But that's what the "<b>Attachments:</b>" below the "<b>Options:</b>" is for: