Problems with SBSAlertCleanup script

I tried installing it on 2 different SBS servers, both 2011. In both cases I receive an error during installation

Set-ItemProperty : Cannot find path 'HKLM:\SOFTWARE\Microsoft\SmallBusinessServer\Admin' because it does not exist.
At D:\\SBSAlertsCleanup v1.0\SBSAlertsCleanup v1.0\SBSAlertsCleanup.ps1:154 char:18
+     Set-ItemProperty <<<<  "HKLM:\SOFTWARE\Microsoft\SmallBusinessServer\Admin" -name "SBSMonitoring-AlertsCleanUp-Up
date" -value "Installed on $date"
    + CategoryInfo          : ObjectNotFound: (HKLM:\SOFTWARE\...essServer\Admin:String) [Set-ItemProperty], ItemNotFo
   undException
    + FullyQualifiedErrorId : PathNotFound,Microsoft.PowerShell.Commands.SetItemPropertyCommand

Exception calling "ExecuteWithResults" with "1" argument(s): "Execute with results failed for Database 'SBSMonitoring'.
 "
At D:\\SBSAlertsCleanup v1.0\SBSAlertsCleanup v1.0\SBSAlertsCleanup.ps1:100 char:37
+     $result = $db.ExecuteWithResults <<<< ("DELETE EventLog FROM EventLog Where EventID=$EventId and SourceID=$Source
Id" )
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : DotNetMethodException

Has anyone else encountered this problem?

yaro