In 2000 he lost a semi-final to Tommy Haas and then let a bronze medal slip through his fingers against Frenchman Arnaud Di Pasquale. Four years later he lost in the second round to Tomas Berdych.
"Last time was quite disappointing, losing in the second round but nevertheless, going there was one of the biggest experiences in life," the Swiss said in Toronto last week.
More used to staying in fancy hotels, Federer appreciates the special feeling of the Olympic Village and says winning gold in Beijing would be one of the highlights of his career.
The Cincinnati is the last chance for major players to boost their game before the long flight to China for the Beijing Olympics, to be followed by a trans-Pacific dash to US Open just over a fortnight later.
World number three Novak Djokovic, having bagged three titles this season, seems to lose some of his steam in the Toronto Masters which saw him slump to Scotsman Andy Murray in the quarterfinals. At Wimbledon, the newly crowned Australian Open winner was also wiped out in the second round.
In women's doubles, Chinese Taipei's Chan Yung-Jan/Chuang Chia-Jung were among the winners, clinching the title of the Tier II Los Angeles Open. The Olympic medal hopefuls have registered three titles to their names this season, and they will pose serious challenge to the hosts China's defending road.
Chinese ace Zheng Jie's run to the women's semifinals at Wimbledon has stoked home hopes of Chinese success. Zheng won the Wimbledon and Australian Open doubles titles in 2006 with long-time partner Yan Zi and will be aiming to repeat the feat of Athens gold medallists Sun Tiantian and Li Ting.
After the Wimbledon, the Chinese women's team are now fine-tuning in north China's Tianjin, and will be back to the Chinese capital early August.
Serbia have high Olympic hopes for women's world number one Ana Ivanovic and number two Jelena Jankovic while Russia have a formidable quartet of Maria Sharapova (3rd), Svetlana Kuznetsova (4th), Elena Dementieva (6th) and Dinara Safina (8th).
The top four players all suffered pre-quarterfinal exits at Wimbledon, the first time that has happened at a Grand Slam in the Open Era.
While Ivanovic, Sharapova and Kuznetsova will be playing for the first time since those losses in this week's Montreal Open, Jankovic played her first summer hardcourt event at Los Angeles last week when she lost to the eventual winner Safina.
The Williams sisters, who have claimed the Wimbledon singles and doubles, are still suffering the injury woes, hoping to recover in time for the Olympics.
Countries are allowed a maximum of six players in the Olympic tournament with no more than four in the singles. They are allowed two doubles pairs.
Tennis was a part of the first modern Olympic Games in 1896 but was withdrawn after the 1924 Paris Games. It returned as a demonstration event in the 1984 Los Angeles Games and became a full medal sport again in 1988.
(Xinhua News Agency July 29, 2008)