As I can recall... in 2009 Federer came back from two sets down in two matches at two different GS.
He came back from behind at the Aussie Open to beat Berdych... then he came back to beat Haas at the French Open.
He does it again this year. Two sets down against Delpo at RG and then the already mentioned comeback at Wimbledon this year.
Not exactly the same in both years but it just shows how good Roger is when it comes to comebacks.
3 Head IG Youtek Prestige MP - Testing Strings