LinuxMCE seems to totally mess up networking during the install. It will take 24 hours or so, but it will install as long as you do an update first, then it will try every repository over and over again for each package it would like to check for updates on.
There needs to be something to address this. I think the best option is not to mess with networking during the install, but perhaps run a post install script or something. Also, a better packaging strategy overall might be to package all the binaries in a single disc or series of discs, and allow an updater to run after the install, or to simply set up a repo and have a "you get everything" meta package, and also allow users to download individual packages. The installer actually makes it much more difficult for "real" linux users, and if it snags there's pretty much no way to walk dummy users through it =)
My two cents.