OK, now it pulls up but yesterday it didn't. Going to go out on a limb here and say something might be wrong with the site. I know that another site I maintain has multiple application servers and until we mounted the wp-content/blogs.dir and uploads directories to a single server we had to do a rsync job to make sure images were same on all 5 app servers. Can you mention this to your hosting provider that images are missing then showing up randomly? I'd be interested to see what they said. You might also ask for a copy of error logs pertaining to your site and specify they look for the red cross image since we saw that one not show up. Yesterdays logs should be good for that.
tim