The factory-safe web server example is designed to support two simultaneous HTTP server sessions. By default, web browsers running on a PC will request no more than two files simultaneously when fetching web content. However, certain software installations can modify this default behavior to allow the PC to open multiple (often in excess of 10) simultaneous connections with the web server. As a result of this, the Nios II web server example may not display all web content properly in the factory-safe example design (for example, images may appear missing from the web pages).
To resolve this issue, ensure that your PC is only opening two HTTP connections. For the Internet Explorer browser, the following Microsoft Knowledge Base article describes the process to increase the number of connections. You may use the same article to verify that your PC is set to only open two connections: http://support.microsoft.com/?kbid=282402.
Alternatively, you may also try another browser, such as Mozilla, whose default behavior is to only open two simultaneous connections to a web server.