http://www.todayszaman.com/tz-web/detaylar.do?load=detay&link=178727&bolum=102
Private Greek television channel Antenne said: “It is not clear whether Erdoğan's illness is real or a diplomatic uneasiness. As a matter of fact, the Turkish prime minister didn't come because of his uneasiness over the EU statements concerning illegal immigrants and his concern that Karamanlis would bring up the issue of illegal immigration during his visit to Athens.”
http://www.hurriyet.com.tr/english/domestic/11914417.asp?scr=1
Erdoğan and Karamanlis were supposed to hold a bilateral meeting Saturday before the opening of the Acropolis Museum. The two leaders were to discuss important bilateral matters as well as the ongoing Cyprus talks.
[...]
The second and more important cause of the cancellation late Friday was the release of the EU presidency’s conclusions regarding Turkey as a source of illegal human trafficking. The report said Turkey had been inserted in the text on Greece’s demand.
One thing the media do not seem to mention is that erdogan would've been in the same room as President Christofias - I don't suppose these two have ever met or spoken at an international gathering before?