Organiser LOCOG last week admitted it had mistakenly oversold tickets for synchronised swimming sessions and was forced to offer thousands of people tickets to other events.
About 10,000 tickets were meant to go on offer in the second round of sales but 20,000 were released instead.
Those who missed out on synchronised swimming have the consolation of a chance of receiving tickets to the track for the men's 100m final, the blue riband event of the Games which is likely to feature Usain Bolt.
Adding to the organisers' blushes, the website for recipients to resell tickets they do not want has been suspended because of technical woes.
An additional one million non-soccer tickets are due to go on sale in April and they are certain to be snapped up.
As the clock ticks down to the July 27 opening ceremony, chief organiser Sebastian Coe said the acid test of his organisation would be whether athletes could be delivered to their event on time, and ready to compete.
"I never want an athlete telling me he did not make a final because the Olympic Village did not create the right atmosphere, or he did not get the right service or the transport did not work," Coe told the Evening Standard newspaper.
"The Games have to work for the most important client group, the athletes."
In already-congested London, few doubt that transport is one of the biggest issues the Games face.
Specially reserved Olympic road lanes - for athletes, officials and media - are designed to ensure competitors are not delayed but their effect is likely to be traffic snarl-ups elsewhere in the capital.
India is expected to send a team after its threat to boycott the Games resulted in an assurance that the branding of sponsor Dow Chemical would not appear on the fabric "wrap" around the Olympic Stadium.
India opposes the company's Olympic involvement because of its links to the 1984 Bhopal gas disaster which killed tens of thousands of people.
- AAP
