No issue here, using safari on the iPad and selecting an image to upload from the photo library on the device.
i do see this message: Note: The maximum size of your custom image is 150 by 150 pixels or 195.3 KB (whichever is smaller).
I have no idea what the size was on my photo, so not sure how much credence to give that warning, but if I was on a PC and could validate the size that would be one thing to check. Also, if you're using the retrieval from URL for a hosted picture on the web, there are sometimes issues with processing the URLs. You might try downloading the image locally and add to profile using the upload option.