VMware backup backs up in the wrong mode (4038812)

Backup is configured to backup in hotadd mode but backs up  2 of the 3 VM’s in hotadd mo0de but backs up one in nbd mode as seen in binary log extract below.

Looking at the corresponding vixDiskLib-xxxx.log file at the time of the backup mode allocation we see “Cannot use advanced transport modes”   because it cannot create a working folder for this VM  in temporary  directory  “C:\Windows\TEMP\vmware-SYSTEM\”

From NetVault binary log:

Job Message   2013/12/12 09:52:15   175   Data Plugin   W2K8T35   TaskID 1u VM disk '[FZ_VMFS03] W2K8T52/W2K8T52-000002.vmdk' opened in 'hotadd' mode

Job Message   2013/12/12 09:52:29   175   Data Plugin   W2K8T35   TaskID 3u VM disk '[CR_VMFS02] W2K8T50/W2K8T50-000003.vmdk' opened in 'nbd' mode

Job Message   2013/12/12 09:52:33   175   Data Plugin   W2K8T35   TaskID 2u VM disk '[FZ_VMFS02] W2K8T51/W2K8T51-000002.vmdk' opened in 'hotadd' mode

From vixDiskLib-xxxx.log file