Incorrect navaid position

Have spent many hours trying to create SID/STARs for Luton. LAst night I got rid of all the FMC errors so this evening checked out what I had created in the ND....arghhhhhhAm I correct in thinking that the 737NG gets all its data from the FMCWP directory?If so is there a known problem with the ND sometimes displaying navaids in the wrong place?I ask because Luton relies on the LUT NDB for most of its procedures.This NDB was missing from the navdata until Richard released V2 of 0309, it now in the list and looking at the LAT/LON appears to be accurately placed.However if I slew the a/c to over LUT as shown on FSNav the ND shows LUT is still about 17ml off and about 15 degrees South of where it should be.Any comments?RgdsDave