Solution : https://service.sap.com/sap/support/notes/734479 (SAP Service marketplace login required)
Key words : 
sap netweaver '04 post installation procedure - jvm settings, /nw04 -> sap netweaver -> release notes, sap netweaver 04 sp stack 04, 0 sp6 sap enterprise portal 6, sap netweaver library, feature pack solution, release notes, sap note 723909, sap note 750360, 40 feature pack
Related Notes : 
       
| 851059 | Related Links do not work in run time. | 
| 814509 | Updates to standard admin roles not applied to Super Admin | 
| 810435 | INavigationNode.getAttributeValue should throw an exception | 
| 793545 | Add object to page loses DL inheritance | 
| 782106 | Migrating from EP60 SP2: Error running JDBC Query iViews | 
| 781239 | Configure SAP BW Report/SAP Transaction iView as D&R target | 
| 779112 | Test connection of WAS or ITS over SSL fails | 
| 773401 | Configuring Portal JDBC System connection properties | 
| 770458 | Drag&Relate backend prerequisites for BW Unifier | 
| 763789 | Improve Portal Performance by Changing Log Levels | 
| 761846 | Lost connection to BW system | 
| 761753 | Systems disappear from the Distributed Query Engine (DQE). | 
| 761751 | Long Time 2 Expand BW system tree in the DQE Metadata loader | 
| 761140 | Working with Page Editor - Save operation flow | 
| 759013 | Special characters in the Personalization friendly name | 
| 759004 | Theme personalization lost after upgrade to EP6 SP6 | 
| 758449 | MSS report throw error | 
| 754699 | |
| 754075 | Connector iViews don't work after upgrade from SP2 | 
| 750360 | SAP NetWeaver '04 SP Stack 04 Portal Platform Patches | 
| 749643 | Preload Business Object metadata for Unification | 
| 749641 | Portal systems are not registered to DQE after upgrade | 
| 748896 | Window features property for external window iviews | 
| 723909 | Java VM settings for J2EE 6.40/7.0 |