Hi Phil, here is a site that will re size the pics, its a pain in the ass but it works.
http://www.picresize.com/
Click > Browes then find & click the pic you want to resize, the click continue.
On the next page go to step 2 "Resize Your Picture:" on the drop down menu click custom size
Then in width and hight make this 500 x590 pixels then click "done resize my picture"
on next page "click save to disc"
you can now upload the pic you have resized to this site.
Like i said its a pain cos you have to do this with every pic you want to upload.
its a way round this problem untill its been fixed, it happend a few time yesterday but at times i found it worked ok then stoped working then it was working ok again.