I just had the right-rear replaced by Subaru last February (went to them becuase I had my MBNA credits). In mid-March the noise started coming back...I think it's the right-rear again.
I knew this would happen....that's why I specifically asked about their warranty, which is 1 year.
I tried to get them to use the Legacy bearing instead, but they would not warranty their work if a non-standard part was used....so I had them put in the POS OE bearing.