Xymon Powershell Windows client

Hi,

I just downloaded the latest version of the Powershell client. I tried to install ist on a 64bit Windows 7 machine. The installation works, but I can't get the service to start.
The first thing is, that powershell complains about the xymonclient.ps1 not being digitally signed. So I set the execution policy to unrestricted. When I try to start the service I get the following message:
PS C:\Program Files\xymon> .\xymonclient.ps1 start
start-service : Fehler beim Starten des Diensts "XymonPSClient (XymonPSClient)".
In C:\Program Files\xymon\xymonclient.ps1:2708 Zeichen:60
+     if((get-service $xymonsvcname).Status -ne "Running") { start-service $xymons ...
+ ~~~~~~~~~~~~~~~~~~~~~
     + CategoryInfo          : OpenError: (System.ServiceProcess.ServiceController:ServiceController) [Start-Service], ServiceCommandException
     + FullyQualifiedErrorId : StartServiceFailed,Microsoft.PowerShell.Commands.StartServiceCommand

When I try to start the service manually with start-service I get:

PS C:\Program Files\xymon> Start-Service XymonPSClient
Start-Service : Fehler beim Starten des Diensts "XymonPSClient (XymonPSClient)".
In Zeile:1 Zeichen:1
+ Start-Service XymonPSClient
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
     + CategoryInfo          : OpenError: (System.ServiceProcess.ServiceController:ServiceController) [Start-Service], ServiceCommandException
     + FullyQualifiedErrorId : StartServiceFailed,Microsoft.PowerShell.Commands.StartServiceCommand

Any ideas what could be wrong?

Dirk