Setting Domain OU

I'm trying to set the value of OSDomainOUName.  It's imbedded as part of an Action sequence;


<Actions>

    <Action Type="DefaultValues" ValueTypes="Net" />

    <Action Type="Switch" OnValue="%XIPGateway%" DontEval="False" >

        <Case RegEx="10.228.64.1">

            <Variable Name="TSVM">VM01</Variable>

            <Variable Name="TSSCH">123</Variable>

        </Case>    

        <Case RegEx="10.228.0.1">

            <Variable Name="TSVM">VM02</Variable>

            <Variable Name="TSSCH">456</Variable>

        </Case>
        <Default>

            <Variable Name="TSVM">VM01</Variable>

            <Variable Name="TSSCH">123</Variable>

        </Default>

    <Action Type="TSVar" Name="OSDDomainOUName">LDAP://OU=Computers,OU=%TSSCH%,OU=OU Name with spaces,DC=HWCDSB,DC=CA</ACTION>

</Action>

If I remove the bolded line the Switch section works.  I've tried moving it above the Default section but it doesn't make a difference.  What am I doing wrong?