Is caching the reason those plugins were taken off the Addon Installer?
What plugins were taken off the Addon Installer? If you're referring to XAI I have only had to remove one broken addon since it's release (don't ask me what it was I really can't remember now!). If you're having any problems with XAI then please completely remove any instances of it on your xbox (plugins>programs and also UserData>Plugin_Data) and then reinstall again.