Solution : https://service.sap.com/sap/support/notes/678751 (SAP Service marketplace login required)
Key words :
merged childrenan empty page, merge id solution, merging twofollowing levels, merging parents, terms mergeid, 0 sp1 hotfix 6
Related Notes :
| 656849 | EP 6.0 SP1 Patch 1 Hotfixes |