737NGX - FSBUILD2 and missing waypoints

Hey there, I'm yet another virtual pilot having a problem with inserting SID's, Stars and waypoints in the FMC. 

I used FSBuild to create a flightplan from EGLL to EHAM (EGLL..BPK.UR123.CLN..UL620..REDFA..EHAM) and exported it to FSX and the 737NGX. Both the game and the the plane accept the route without any problem (using flight planner in FSX and co route in the FMC), However for the sake of realism I want to insert the route into the FMC myself. 

Now I hit my problem: When I load the co route in the FMC it gives me the following route:

VIA          TO

DIRECT   BPK

UR123     CLN

UL620     REDFA

DIRECT   RW36L

When I try to copy this result and put in the second waypoint line in RTE (page 2), UR123 in the VIA box on 2L the FMC gives the error 'INVALID ENTRY'. 

Why?

I allready updated the navdata using navigraphs latest cycle and their program 'Navigraph FMS Data Manager". Why does the FMC accept the route from FSbuild but not from me?