Only WPP ignore this parameter.WPP doesn't ignore your command-line. See your WindowsUpdate.log :
2013-08-19 08:04:14:881 4420 13b4 Handler MSI final command line: REGISTER_NO_MSO_TYPES=1 CREATEDESKTOPLINK=0 SETUP_USED=1 COMPANYNAME="Bad Wurzach" USERNAME="EDV" ADDLOCAL=ALL REMOVE=gm_o_Winexplorerext,gm_o_Activexcontrol,gm_o_Quickstart,gm_o_Javafilter,gm_o_Pyuno,gm_o_Pyuno,gm_o_Onlineupdate /lv "C:\temp\oo4.log" ALLUSERS=1 MSIRESTARTMANAGERCONTROL=Disable REBOOT=REALLYSUPPRESS
openoffice400.msi is not able to treat the parameter "REGISTER_NO_MSO_TYPES=1" when it is launch by Windows Update Agent.
