Harsh punishments for North Korea?

Last week the FIG outright banned North Korea from entering gymnasts in any FIG competitions until October 2012. This 2 year ban was given in response to gymnast Su Jong Hong being previously entered in competitions with Three different birth dates varying from 1985 - 1989.

Her 'official' birthdate at the 2010 world championships of March 9 1989 would have made her ineligible for the 2004 olympics where she competed with the birthdate of 1985. Hong's sister (and if her recent birth year is to be believed twin sister) Hong Un Jong won gold on vault at the 2008 Beijing olympics.

On top of the 2 year national ban. Su Jong Hong has also been banned from all competition (including nationally). She is herself a world silver medallist on Vault (2007).

Similar questions were raised in 2008 when the dates of birth of the diminutive chinese gymnasts were called into doubt. Websites showing younger birthdates were rapidly removed from the internet. The FIG and IOC concluded there was no rulebreaking in that case. However the 2000 chinese olympic team were stripped of their bronze medals after Dong Fangxiao was found to be underage.

Currently the FIG and IOC take a passport to be valid proof of age. Is this enough to prevent age fraud when countries have a vested interest in their athletes competing?
What other age checks could be useful or viable and was the FIG's punishment of all North Korean gymnasts justified?