2662964 - DBSQL_DUPLICATE_KEY_ERROR in CL_RSSH_HIERARCHY_BASE during hierarchy load

Loading a hierarchy via Data Transfer Process (DTP) or Infopackage, fails with the following dump:

"DBSQL_DUPLICATE_KEY_ERROR" CX_SY_OPEN_SQL_DB
"CL_RSSH_HIERARCHY_BASE========CP" bzw. CL_RSSH_HIERARCHY_BASE========CM00G
"SAVE_HIERARCHY"

The dump can happen in any of the following lines in the SAVE_HIERARCHY method:
INSERT rshiedirt FROM TABLE p_sx_htabs-t_hiedirt.
INSERT rsmhiernode FROM TABLE p_sx_htabs-th_hiernode.
INSERT rsthiernode FROM TABLE p_sx_htabs-th_hiernodet.
INSERT rshielvt FROM TABLE p_sx_htabs-t_level.
INSERT (p_sx_hieprops-hietab) FROM TABLE <l_th_htab>

• SAP NetWeaver 7.3
• SAP NetWeaver BW 7.31   (SAP NW BW 7.3 EnhP 1)
• SAP enhancement package 1 for SAP NetWeaver 7.3
• SAP NetWeaver BW 7.40
• SAP NetWeaver 7.40
• SAP NetWeaver 7.50

CL_RSSH_HIERARCHY_BASE, duplicate, double, duprec, HIERARCHY, HIEID, l_th_htab, L_S_HIEDIRCOM, RSHIEDIR, RSHIEDIRT, RSMHIERNODE, RSTHIERNODE, RSHIELVT, RSH1 , KBA , BW-WHM-DBA-HIER , Hierarchy Processing , BW-WHM-DST-DTP , Data Transfer Process , Problem