When installing SQL Server 2008 R2 from the command line prompt, I am getting the following error that is recorded in the Summary file.

Scenario specific rules:

Rules report file:               C:\Program Files\Microsoft SQL Server\100\Setup Bootstrap\Log\20101217_131444\SystemConfigurationCheck_Report.htm

Exception summary: The following is an exception stack listing the exceptions in outermost to innermost order Inner exceptions are being indented

Exception type: System.ArgumentNullException
    Message: 
        Value cannot be null.
        Parameter name: path2
    Data: 
      DisableWatson = true
    Stack: 
        at System.IO.Path.Combine(String path1, String path2)
        at Microsoft.SqlServer.Configuration.SqlEngine.SqlEngineSetupPublic.RecomputeDirectoryPaths()
        at Microsoft.SqlServer.Configuration.SqlEngine.SqlEngineSetupPublic.Calculate()
        at Microsoft.SqlServer.Configuration.SetupExtension.FinalCalculateSettingsAction.ExecuteAction(String actionId)
        at Microsoft.SqlServer.Chainer.Infrastructure.Action.Execute(String actionId, TextWriter errorStream)
        at Microsoft.SqlServer.Setup.Chainer.Workflow.ActionInvocation.ExecuteActionHelper(TextWriter statusStream, ISequencedAction actionToRun)

Has anyone seen this.

Here is what I am sending for the command line parameters.

/q /ACTION=Install /FEATURES=SQLEngine /SECURITYMODE=SQL /SAPWD="myPassword" /BROWSERSVCSTARTUPTYPE=Automatic /SQLSVCSTARTUPTYPE=Automatic /SQLSVCACCOUNT="NT AUTHORITY\Network Service" /SQLSYSADMINACCOUNTS="BUILTIN\ADMINISTRATORS" /AGTSVCACCOUNT="NT AUTHORITY\Network Service" /IACCEPTSQLSERVERLICENSETERMS