[Crashpunk]

The file size limit on the avatar/sigs is stupid but you can get around it.

What I do is use other people's sigs as a template for the dimensions then put my own image on it. I use Photoshop to save it as the right file (usually JPEG) if it's too big, I go back and save it again but make the quality slightly worse until its compatible with the forum.

It also depends on what the image you have. If it's a hectic picture i.e. Has a lot of stuff on the image, it will have lots of pixels making the file size will be massive. I find it a lot easier to have a transparent sig like mine saved as a PNG. Sigs like mine are tiny in file size because it's just text.

Just keep trying, it's mostly down to the file your saving it as.