Backing up VMWare Virtual Machines

Hi All,

I have a number of VMWare Virtual machines that need to be backed up nightly.  I have a job setup that targets the vSphere center machine and whiel it appears to back up I always get this message against each GUEST:

Backup Exec failed to connect to virtual machine '\(DC)name of domain(DC)\vm\SageServer' and was unable to collect the necessary metadata to restore individual application items. You cannot perform GRT-enabled restores of application data from this backup. You must install the Agent for Windows and the virtual machine tools provided by your host software on the virtual machine.

Any ideas on how to get this to work so that I can do a file level restore if needed?