THE BLACK SHORE was originally titled PARADISE, but somebody thought that was too close to Melissa Scott's THE GARDEN.
THE EUGENICS WARS came dangerously close to just being titled KHAN: THE RISE AND FALL. (I actually have a mock-up of a cover with that title on my office wall.)
My TERMINATOR novel went from DARK SKY to COLD STEEL to COLD WAR before it finally saw print.
And TOMORROW SUCKS (my scifi vampire book) started out as a joke title before somebody finally suggested, "Hey, why don't we REALLY call it that?"
These things happen. Titles are just something that get tossed around until one stands out.