I had flights from SFO to Moscow by United and Lufthanza airlines on September, 2013. When I tried to get miles on my accounts for the flights I got only a portion for the first segment, SFO-FRA operated by United. When it came to flights operated by Lufthanza it turned out that they didn't credit miles for some types of flights. There are no warnings about such a policy on travel sites such as Orbitz.
So be aware that you will NOT be got credited for some types of flights operated by Start Alliance members even if you have valid Mileage Plus account with United.
Really frustrating practice, talked to Sr. Director of Mileage Plus dept of United, name is Mishe, ID# V037250; feel like airlines take every opportunity to fool customers around.

/-\/