Not sure if this is common knowledge at this stage or not, but just read this today from an interview with Harrington:
"It certainly has been difficult between me and Sergio. Things definitely got a bit tense there, but the Ryder Cup really helped. We spent the week in each others company, played a couple of practice matches together and he got to say his piece that he wanted to say all along. Some of the lads eventually drew it out of him - not least because one of the pictures in the team room was of me holing that putt at the US PGA - and he got to tell me that he really wanted to smash that putter over my head! That was what I really wanted to hear and though the Ryder Cup didn't do much for Europe, it did do a lot for me and Sergio"
Good to see Europe's top two golfers might be back on good terms.....at least until the next time Harrington pips him at the post in a major :-) !