1) Is your file is in .tga? If yes convert it with a image prog.
2) Follow this rules in sig size:
Keep your Sigs at a reasonable size, both in dimensions and size
in Kb's. Please be aware there are a number of 56k users out there.
New Sig size restrictions are as follows : Sig dimensions will now be
550x125, and the file size will be, at a maximum, 100kb. Please
follow these rules.
3) Upload it at:
http://www.dodstudios.net/uploads/upload.php
4) Now go in your profile and put your image code in it.
Example:[img]http://www.dodstudios.net/uploads/uploads/yourimage.jpg[/img]
Hope it help.