I had this prob too..
1. you have to open the picture up by itself in a seperate window
2. copy the address from that window
3. go to the edit signature section in user cp
4. click on the icon of the mountains above the white box where your sig goes
5. lastly paste the address of the pic in the pop-up url box that appears
and wala!! you have a piture in your sig!!!
hope this helps -mike
<FIELDSET class=fieldset><LEGEND>Visible Post Elements</LEGEND><TABLE cellSpacing=3 cellPadding=0 width="100%" border=0><TBODY><TR><TD>You have the option to show or hide various elements of messages, which may be of use to users on slow internet connections, or who want to remove extraneous clutter from posts.</TD></TR><TR><TD><LABEL for=cb_showsignatures><INPUT id=cb_showsignatures type=checkbox CHECKED value=1 name=options[showsignatures]>Show Signatures</LABEL>
<LABEL for=cb_showavatars><INPUT id=cb_showavatars type=checkbox CHECKED value=1 name=options[showavatars]>Show Avatars</LABEL>
<LABEL for=cb_showimages><INPUT id=cb_showimages type=checkbox CHECKED value=1 name=options[showimages]>Show Images (including attached images and images in code)</LABEL>
</TD></TR></TBODY></TABLE></FIELDSET> <FIELDSET class=fieldset><LEGEND><LABEL for=sel_threadedmode>Thread Display Mode</LABEL></LEGEND></FIELDSET>[/left]