Because the materials at Warners are missing 10 minutes. The film was reissued in 1948. It was trimmed to fit a double bill with (also edited) THE SEA HAWK. Hal Wallis' name was also removed from the main titles. John Garfield's 16mm print is complete and it was donated to NYU. I believe Warners has accessed it but they're hoping to get 35mm materials from England.
Because Warner is trying to locate better quality elements for the original long version of the film; it's the same basic thing that has prevented THE BIG SKY from getting released.
EDIT: D'oh! Ray Fiola and I must have been writing our replies at the same time. Oh well, his response is the far better one . . .