Have never come across a case when the cache for a website belongs to the proxy server. Here is what I mean. I have a site: http:// mysite.com and Google delivers cache from http:// irfansurf.appspot.com/mysite.com Any Idea on that? Am I hacked?
Maybe this is because of some redirect?! Check your .htaccess for any 301, 302 redirects that you did not make yourself. If someone hacked it, the SE's might have got it indexed while being redirected. Once, one of my sites was redirected that way - only for a couple of hours each day. Happily I noticed it exactly during that time...
Ok, I have discovered that Google Cache for other pages of the website is also different from the URLs themselves. For one page it shows the URL of our banner on a different domain.. How is that possible?