Someone was abusing the option in signatures and posting a really wide signature image which distorted the whole layout, so I took away the option, blame Maverick ;)
Nah it's all good I was planning on removing it anyway because I knew it would happen eventually. BUT, if you go to your User CP and Edit Signature you can now upload a signature image, or point to the URL of one you want to use, and use that instead. But, to ensure it doesnt stretch the site design, I have limited the dimensions to a maximum 450 width.