Script failes after running perfectly for some time

Hi.

I hope you can help me.

We are trying to create a powershell script, that can create all our new VM's.

The problem is, that this script runs perfectly for some time, and then fails constantly afterwards.

We can create 5 - 10 VM's before it fails.

When it then fails, it still creates the VM, but fails to change network adapter, or start the VM.

The scripts is :

-

Add-PSSnapin VMWare.vimAutomation.Core

Remove-Variable -Name * -Force -Confirm:$false -ErrorAction silentlycontinue 

$VISRV = Connect-VIServer viappdk001.ad.nss.nnit.com -password xxxxxxxxx -User Vmware_SDS_createvm > $null

$Obj_RNDNAME = New-Object  System.Random

$RNDNAME = 'VM'+$Obj_RNDNAME.Next()

New-VM -VMHost nssvmdk009.ad.nss.nnit.com -Name $RNDNAME -GuestId winLonghornGuest -diskmb 50000 -MemoryMB 1024 -NumCpu 1 -Server $VISRV 

$adapter = Get-NetworkAdapter -VM $RNDNAME

Remove-NetworkAdapter -NetworkAdapter $adapter -Confirm:$false

$vm = Get-VM $RNDNAME

New-NetworkAdapter -VM $vm -StartConnected:$true -Type Vmxnet3 -NetworkName "VM_Deployment_Vlan999" -Confirm:$false

Start-VM -VM $vm -Confirm:$false

Disconnect-VIServer -Confirm:$False

Remove-Variable -Name * -Force -Confirm:$false -ErrorAction silentlycontinue 

-

When it fails, we get the following error messages.

-

Cannot add Windows PowerShell snap-in VMWare.vimAutomation.Core because it is already added. Verify the name of the snap-in and try again.

At :line:1 char:12

+ Add-PSSnapin <<<<  VMWare.vimAutomation.Core

WARNING: There were one or more problems with the server certificate:

• The X509 chain could not be built up to the root certificate.

7/15/2010 9:59:07 AM     New-VM          Unsufficient permissions. You need 'System.Read' privileges to complete the requested operation.     

At :line:9 char:6

+ New-VM <<<<  -VMHost nssvmdk009.ad.nss.nnit.com -Name $RNDNAME -GuestId winLonghornGuest -diskmb 50000 -MemoryMB 1024 -NumCpu 1 -Server $VISRV

-

I can see that this i a permision thing, but the script runs fine the first 5 - 10 times.

The account is not locked out, and i can log on to vCenter, and perform the came actions manualy, that the script is suposed to do, before and after the script fails.

Any ideas ?

Thanks

/Robert