The eagerly awaiting new Indiana Jones movie won't be released for another two years, because producer George Lucas isn't happy with the script. Indiana Jones 4 has been in the works for a number of years but looked likely to hit screens next year after Lucas recruited star Harrison Ford and original director Steven Spielberg for the project, and hired Frank Darabont to write a screenplay.
But Lucas has sent the Shawshank Redemption writer back to the drawing board. A studio source reveals, "Indiana Jones 4 was meant to start shooting this summer but won't now be coming out until 2006. Even though Harrison and director Steven Spielberg were happy with the screenplay, Lucas still doesn't like the final act and wants a faster pace and more action."

Source: Press Release