Hi,
Are these SUSE machines being virtualized by VMware?
Just a note that linux agent will not detect any virtualization if it is running on machine that is virtualized by non-vmware product.(like virtual box )
Check if it is not the case.
Also please run following tool on affected machine to check if it detects VMware releated staff :
/opt/altiris/notification/nsagent/lib/helpers/vmware
Thanks,
Andrei