I've been trying for an hour to change my signature picture. My current one is 985 x 256 pixels. My new one I've tried in numerous sizes ranging from the same, down to 500 x 124. When pressing the 'upload' button, it goes through the motions, but it doesn't upload. Just leaves my exsiting signature as is, despite me ticking the box to delete it.
What am I doing wrong, and what is the size limit you are allowed??