While cleaning up a client computer I found an issue with Internet Explorer where the proxy seeting could not be changed with out it automatically reverting back to its original setting. This persistant issue seemed related to a typical group policy setting but this was not possible because the system was running Windows 7 Home. Many others on the Internet had reported the issue with only one resolution, editing the registry.
The registry changes didn't seem to be long lasting until I found an article by Philip Turner that provided some additional registry keys that I was missing in my search.