Mr Bush is well known for his verbal slips
To seasoned Bush watchers, a slip of the tongue is nothing new but the US president's mistake in Japan sent a shiver through jittery markets.
The White House dismissed the president's reference to discussing the "devaluation issue" as a verbal gaffe but his words led to a brief rush to sell the Japanese yen on international currency markets.
Aides hastily pointed out that he had meant to say "deflation".
Mr Bush recently promised American voters: "Not over my dead body will they raise your taxes". He also declared: "I'm a free trader. I will work to end terriers and barriffs [tariffs and barriers] everywhere, across the world".
The president once infamously pointed out that "more and more of our imports come from overseas". And reaching out to the smaller scale businessman, he also pledged: "I understand small business growth - I was one."
Gaffes
Recalling the last statement, Mr Bush later admitted: "I don't have the slightest idea what I was saying."
The president's widely reported verbal clangers have become known as "Bushisms" and have spawned at least one book devoted to the subject.
But while some commentators dismiss such gaffes as harmless slips, others are concerned that they portray the president as someone ill-suited to handling delicate international affairs.
Shortly after the attacks on the US, Mr Bush attracted criticism by initially describing the war against terrorism as a "crusade" and labelling Osama Bin Laden as "the evil one".
In the aftermath of 11 September, Mr Bush appeared to struggle to find words to sum up the national mood and made copious references to "smoking out" these "folks" who had perpetrated the attacks.
Appeal
Asked at a press conference what security advice he had for Americans in the light of the later anthrax attacks on Washington, the president replied: "You know, if you find a person that you've never seen before getting in a crop-duster that doesn't belong to you, report it."
But confounding his critics, Mr Bush's personal touch and handling of the aftermath of 11 September seems to have swept aside the misgivings of many.
There are even signs that some Americans take what Mr Bush refers to as "my accidental wits and wisdom" as an intrinsic part of his appeal.
And according to opinion polls, the president's approval rating is currently riding high at a near-record 86%.