Like I said, the image wasn't updating for us. Upload it as a different file name and put it in your signature. Here are the signature guidelines so you make sure you get it right:
7) Signatures must adhere to the following specifications:
* Text signatures may not exceed 15 lines in size 1, or 8 lines in size 2. Text size 3 and above is not allowed. Text size 1 may only be used with a graphic.
* The combined size of all images in a sig is a maximum of 468x120. Please keep the file sizes small for loading times.
* Any scripts that display a user's IP address and browser information are not allowed.
* Signatures are subject to Rule 3.