Why can't I upload an image for my signature?

I have been able to type in text for my signature, but under Signature Permissions it says I cannot upload images. I have been a member for over 30 days and have more than 100 posts, so I don't think it's an issue of being too new.

Do I have to be a paid member? Or maybe put the image in Photobucket first? Any suggestions would be appreciated.

Thanks

my suggestion would be to load the image into Photobucket and then just copy and paste the url with the image tags into your signature, just like you post pics