"DOMAIN\\USER" should also work as well.
You should only have VMmark VMs in your VMmark cluster. The only VMs there should be named according to VMmark's naming standards and should be:
DS2DBN
DS2WebAN
DS2WebBN
DS2WebCN
MailserverN
OlioDBN
OlioWebN
StandbyN
where N is the tile number.
The other VMs in your cluster are probably causing ListVMs to not complete correctly. Please move any other VMs to a different cluster. If you have further problems at this step, please attach a zipped copy of your results file to this thread so we can troubleshoot more thoroughly.
Thank you,
Rebecca