Or ATTACH PICTURES to your posts.... you have more than likely violated the signature limitations clearly outlined in the RULES AND REGULATIONS:
13. Please maintain respectable size signatures within the limitations set hereforth.
As a result, your account has been locked prohibiting your from editing your account (and subsequently changing your signature) as well has losing the functionality to utilize the SEARCH feature and attaching pictures to your posts from your harddrive.
For directions on how to resolve this issue... please follow the instructions provided in the "Dude, Where's my sig" post stickied in this forum:
Thanks for your cooperation.