If the pixel dimensions your gave are right W 4070 x H 32305,
then the document is too big for pse9.
Elements will only open documents of 30,000 pixels on less,
either width or height. In other words if the document size is greater than 30,000
pixels in width or 30.000 pixels in height, photoshop elements won't open the file.
Newer versions of the full photoshop can handle documents of 300,000 pixels.
When i said newer versions of photoshop, that would apply to cs and newer.
Also the 30,000 pixel limit in photoshop elements applies to any file format, not just pngs.