I've downloaded the SQL Server 2008 R2 software from Microsoft and am working on scripting a silent installation. I'm getting the following errors (and the duplicate paste job is not an accident, that's how it shows up for me)

The following error occurred:
Exception has been thrown by the target of an invocation.

Error result: 1152035024
Result facility code: 1194
Result error code: 43216

Please review the summary.txt log for further details
The following error occurred:
Exception has been thrown by the target of an invocation.

Error result: 1152035024
Result facility code: 1194
Result error code: 43216

Please review the summary.txt log for further details
Microsoft (R) SQL Server 2008 R2 Setup 10.50.1600.01

This is what shows up in the detailed SQL install log.

2011-02-23 09:53:13 Slp: Running Action: ExecuteInitWorkflow
2011-02-23 09:53:13 Slp: Workflow to execute: 'INITIALIZATION'
2011-02-23 09:53:13 Slp: Error: Action "Microsoft.SqlServer.Configuration.BootstrapExtension.ExecuteWorkflowAction" threw an exception during execution.
2011-02-23 09:53:13 Slp: Microsoft.SqlServer.Setup.Chainer.Workflow.ActionExecutionException: Exception has been thrown by the target of an invocation. ---> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.ArgumentNullException: Value cannot be null.
2011-02-23 09:53:13 Slp: Parameter name: InstallMediaPath

Hopefully someone can help me work through this. Here is a simple version of my PowerShell code.

$arguments = @()
$arguments += "/q"
$arguments += "/ACTION=Install"
$arguments += "/FEATURES=SQL,Tools"
$arguments += "/INSTANCENAME=MSSQLSERVER"
$arguments += "/SQLSVCACCOUNT=`"$NetBIOSDomainName\$SQLServerServiceAccount`""
$arguments += "/SQLSVCPASSWORD=`"$SQLServerServiceAccountPassword`""
$arguments += "/SQLSYSADMINACCOUNTS=`"$NetBIOSDomainName\$SQLSysAdminAccount`""
$arguments += "/AGTSVCACCOUNT=`"$NetBIOSDomainName\$SQLServerAgentAccount`""
$arguments += "/IACCEPTSQLSERVERLICENSETERMS"
Start-Process "$SQLServerSetupLocation\setup.exe" -Wait -ArgumentList $arguments -RedirectStandardOutput error.txt