I am quoting (below) from the link you provided; I have added italics to indicate the quoted text and boldface to emphasize some of it.
One may wonder: where did this false interpretation originate? Who is responsible for the translation that has sparked such worldwide controversy? The answer is surprising.
The inflammatory "wiped off the map" quote was first disseminated not by Iran's enemies, but by Iran itself. The Islamic Republic News Agency, Iran's official propaganda arm, used this phrasing in the English version of some of their news releases covering the World Without Zionism conference. International media including the BBC, Al Jazeera, Time magazine and countless others picked up the IRNA quote and made headlines out of it without verifying its accuracy, and rarely referring to the source. Iran's Foreign Minister soon attempted to clarify the statement, but the quote had a life of its own. Though the IRNA wording was inaccurate and misleading, the media assumed it was true, and besides, it made great copy.
And a little further down in the article:
The inconsistency of the IRNA's translation should be evidence enough of the unreliability of the source, particularly when transcribing their news from Farsi into the English language.
So we have The Islamic Republic News Agency, Iran's official propaganda arm providing an "unreliable" translation of Ahmadinejad's quote of a statement formerly made by Khomeini. Right.
And we are to therefore conclude that "western media" is at fault for reporting this translated text to the rest of the world? Right.
Therefore I conclude:
In Iran we don't have unreliable translations like in your country. :-)