"some map makers intentionally include phantom streets to prevent 
copyright infringements, that was was not usually the case with nautical
 charts because it would reduce confidence in them."
hmmmmmm...interesting
JK's first thoughts were: "what?  global warming caused the island to sink?"
That may be possible, but prob. not the cause here. 
22 November 2012
Last updated at 10:57 GMT  
 
South Pacific Sandy Island 'proven not to exist'
   Cartographers everywhere are now rushing to undiscover Sandy Island for ever
    Cartographers everywhere are now rushing to undiscover Sandy Island for ever 
A 
South Pacific island, shown on marine charts and world maps as well as 
on Google Earth and Google Maps, does not exist, Australian scientists 
say.
The supposedly sizeable strip of land, named Sandy Island on 
Google maps, was positioned midway between Australia and French-governed
 New Caledonia. 
        
But when scientists from the University of Sydney went to the area, they found only the blue ocean of the Coral Sea. 
        
The phantom island has featured in publications for at least a decade.
        Scientist Maria Seton, who was on the ship, said that the team was expecting land, not 1,400m (4,620ft) of deep ocean. 
        
"We wanted to check it out because the navigation charts on 
board the ship  showed a water depth of 1,400m in that area - very 
deep,"  Dr Seton, from the University of Sydney, told the AFP news 
agency after the 25-day voyage.
        
"It's on Google Earth and other maps so we went to check and there was no  island. We're really puzzled. It's quite bizarre.
 
complete article at: http://www.bbc.co.uk/news/world-asia-20442487