I was just checking scores of davis cup 2010 semi-finals. The last(5th) rubber in the France Vs Argentina match was won by Clement who beat Zeballos 7-5 6-1, so they played best of 3 sets.

But checking the last(5th) rubber match in Serbia Vs C.Republic, Tipsarevic leads 2 sets to 0, and they are playing a 3rd set, so why are they playing a best of 5 sets in last rubber, where everyone els is playing best of 3 in there last rubber match.

@Sam, thanks for that.