what kind of pools you are creating? floating or Dedicated? how do you customize desktops (sysprep or quick prep)?
before it goes to Agent unreachable , it will stuck in place and after sometime it shows agent unreachable, is that true
1- have a look in this KB
2- check that gold Imaged dose not have static IP address
It's a manual pool with floating user assignment so there's one VM from vcenter with 4 users assigned to it (they don't all connect at the same time).
It will say agent version unknown and waiting for agent.
I deleted the VM and rebuilt it from scratch. Seems to be working now.