Can not install Novell BorderManager 3.9 Support Pack 2

Installing NBM39SP2 patch, only the backup without the installation of the service pack was done. No new files were installed
The BM39sp2.log showed:

-------------------------------------------------------------------------
| Novell BorderManager 3.9 Support Pack 2
--------------------------------------------------------------------------
Begin logging for the Novell BorderManager 3.9 Support Pack 2 installation.
  Backing up SYS:SYSTEM contents
  Backing up SYS:PUBLIC contents
  Required version of iManager not found : iManager plug-in files not copied.
  Updated PRODUCTS.DAT
Completed install of Novell BorderManager 3.9 Support Pack 2
--------------------------------------------------------------------------
End logging for the BorderManager 3.9 Support Pack 2 installation.
--------------------------------------------------------------------------

and products.dat got updated with the new nbm39sp2 entry

This is only seen on servers where there is no iManager installation. The install routing tries to backup the iManager modules and as it did not find them, it halts the installation.
As a workaround, install the support pack without the backup option. This will allow the complete install of sp2.