B757-200
Flight Crew Air Transport Pilot (ATP)
Human-Machine Interface; Other / Unknown
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued Advisory / Alert; Flight Crew Returned To Clearance
Human Factors; Procedure
The flight plan would not load through ACARS into the FMS so I manually entered the flight plan.  I entered the waypoint KD45O as KD54O; I  was distracted by the O (oscar) at the end; being certain to enter an O (Oscar) instead of a 0 (zero).  When the Captain read the waypoint  back during the legs check; I again missed the transposition of the 45.  As we turned over DBL to KD54O Denver Center said ' I show you off course; verify KD45O';  we immediately saw the mistake and  proceeded on course.  Their we're no other aircraft in our vicinity.
The First Officer was unable to upload flight plan via ACARS.  He then loaded the plan manually and incorrectly entered waypoint KD45O as KD54O.  During preflight Checks I read waypoints from FMC and and the  First Officer verified from printed plan.  When PDC came via ACARS only the first few fixes were listed; followed by 'as filed'.  After passing DBL; Denver Center asked if we were proceeding to KD45O and we immediately realized our mistake and promptly reentered the correct waypoint.  TCAS showed no aircraft in our area.  The course correction was less than 10 degrees.  These created waypoints require special attention as opposed to VOR's and named fixes.  The last safety net would have been a full PDC.
B757 flight crew describes a track error caused by a NRS waypoint FMS entry error.