Typemock NCover Nant Task problem.

I have the following nant build(nunitTypemock.build) file, taken from example here:
 

<xml>
<project>
   <property>
   <property>
   <property>
  
  <Example>
    <target>
    <Dynamically>
    <loadtasks>
    
    <Load>
    <loadtasks>
    
    <Start>
    <typemockstart>
    
    <Run>
    <ncover>
    <Stop>
    <typemockstop>
  </target>
</project> 

And I have NCover 3.0 installed.

To run an Nant task, I type in

"C:Program Files
antin
ant.exe" /f:"D:/nunitTypemock.build"

And I got a "return code was -100" error. I looked through the log and it seems that nunit cannot run because of the following exception:

System.NullReferenceException: Object reference not set to an instance of an object
at NUnit.Core.SimpleTestRunner.CountTestCases(ITestFilter filter)

Anything I did wrong?

I use NCover 3.0, instead of NCover 2.0, not sure whether this is the problem.