[wix-users] Wrong Powershell version

[jovan27 at gmx.de]

Hi,

I have the following in my product.wxs to check the installed PSVERSION on my machine

// WixPSExtension
<PropertyRef Id="POWERSHELLVERSION" />
    <Condition Message="[POWERSHELLVERSION]">
      <![CDATA[Installed OR POWERSHELLVERSION <= "1.0"]]>
    </Condition>

During install it shows:  2.0

Get-Host | Select-Object Version gives me:

Version      
-------      
5.1.18362.752

What is wrong with my XML?

Also I don't understand the condition from above: 

1. Installed - For me it sounds like, if is installed (but in reality it executes only if "not installed")
2. why `or` ?