Netbackup services Hung/multiple bpclntcmd.exe process running

Hello, Of late we are experiencing this issue on number of our WIndows 2k3 and 2k8 servers where the Netbackup services just go hung and do not start . when we try to start them manually, error like failed to start the dependency and the services do not start started in timely fashion occurs. Also on many servers bpclntcmd.exe multiple processes could be seen running. We try to kill them manually but that wont work. We have McAfee shiled 8.8 running on the servers and have the nbu processes excluded from the scan. Any goood resolution apart from upgrade or reboot. We have to reboot the server for getting the backups running but we cannot do this everytime since these are prod servers. All the server are at NBU 7.1.0.2 including master/media(linux machines) PS- 7.6 upgrade project is in place and will upgrade severs in few month time.