This is strange. I was just browsing around Webmaster Tools in the url removal section and upon clicking the list of different sites (in the top right corner), I saw a list of sites belonging to someone else, all in Spanish and all linking to the ES (hl=es) version of Webmaster Tools.
I can't reproduce this, but both worrying and strange. I'm going to take a stab and suggest there might be some session security issues.
*moderator: No idea which forum to post this but here.