NWBC 4.0 PL12 is now available for download from SAP Service Marketplace: http://service.sap.com/patches
-> Support Packages and Patches -> A - Z Index -> "N" -> NETWEAVER BUSINESS CLIENT -> NWBC NW BUSINESS CLIENT 4.0 -> Win32
PL 12 contain fixes in topics like
- Transaction handling when webdispatcher is involved
- Certificate handling for internal ABAP runtime webservices
- Detection mechanism for MS Internet Explorer versions
- Side Panel
- Favorite navigation
- Portal connection
- NWBC User Interface
For more details on all the above, see SAP Note 1707626
