What is the validity of the statement that the Ramadan fast of the year 1432 AH, corresponding to August 2011 CE, was invalid, and that making up for that day is obligatory?

The beginning of the month of Ramadan depends on sighting the crescent moon or completing thirty days of Sha'ban, as the Prophet, peace and blessings be upon him, said: "Fast when you see it (the crescent moon) and break your fast when you see it. If it is obscured from you by clouds or darkness, then complete the number [of days], the number of Sha'ban." So, if Muslims fast with the people of their country based on a legitimate sighting and complete twenty-nine days, their fasting is valid, and no make-up days are required of them.