Why am I seeing a red "X" where the image should be?

Install Java form java.com (free).  If that does not resolve the problem, refer to:

www.java.com/en/download/help/redximage.xml

Optionally, on firmware 1.1.61 and higher, you can select Javascript mode (the default), which does not require Java and can be viewed on virtually any browser or system (when viewing the camera directly), including iPhone.