I have 22 host servers... 2 of which are running 3.0.2 - Build 61618.
Every couple of days, those two servers lose connection to Virtual Center (currently running VC 2.0.2 Build 50618). Restarting the mgmt-vmware service always fixes the problem, but it re-occurs a few days later.
Is this a known bug? Do I need to upgrade Virtual Center? Or downgrade the two host servers?
i would go for an VC upgrade either 2.0.2 update 2 or to VC 2.5 which also can manage ESX 3.5 hosts.
For a quick fix with no downgrade of any ESX-host or upgrade of VC, you also could add a cron job which restart the mgmt-vmware every day or something.