Here you will find a list for the most recent patches available for Network Node Manager and Operations Manager for UNIX (formerly OpenView Operations UNIX) products.
URLs of interest:
HP Software Patches http://support.openview.hp.com/selfsolve/patches (HP Passport sign-in required)
IT Resource Center Forum OV Network Node Manager http://forums.itrc.hp.com/service/forums/categoryhome.do?categoryId=165
IT Resource Center Forum OV Operations (ITO) http://forums.itrc.hp.com/service/forums/categoryhome.do?categoryId=162
Special Note on NNM 7.53