Alternatively, you can use IP : port style proxies (e.g. 72.188.110.83:80) instead of a web based CGI or PHP proxy, which can handle any content on the web page you are viewing.
It requires a BIT more work to set up HTTP ip : port style proxies because you need to go into your browser settings and set the active proxy. If you google for your browser and proxy setup (e.g. "mozilla proxy setup") you should be able to find some resources.
You can also try Proxy Multiply in my signature which features a button, 'Set As Active Proxy', that does the configuration for you after you test a proxy and select a nice fast one to use for web browsing.