Compiler Errors: Namespaces not recognized by the NAnt "booc" task

Hi all,

I want to compile my Boo project via the "booc" task in NAnt instead of 
using the Sharp Develop IDE.

My project has got it's own namespace ("my_namespace") and subnamespaces 
such as "my_namespace.personalized" or "my_namespace.sub2".

When calling the NAnt booc task, I get following error messages, so that 
the program doesn't compile properly.
Example:
"[booc] U:\.....\src\Qualityreport.boo(7,8): BCE0021: 
Boo.Lang.Compiler.CompilerError: Namespace 'my_namespace.personalized' 
not found, maybe you forgot to add an assembly reference?"

And a few lines above, the  console tells me this:
"[booc]     U:\.....\src\Qualityreport.boo(7,8): import reference 
'my_namespace.personalized' bound to error."

So what's wrong..? How do I include my sub-namespace?
Is it by using the "references" element in the NAnt booc task? But how?

Here's my NAnt code:
<?xml version="1.0" ?>
<project name="myProj" default="build">   
    <property name="boo.dir" value="D:\Programe\boo-0.8.2\bin" />
    <property name="projectDir" value="U:\.....\" />
    <property name="srcDir" value="${projectDir}/src" />
    <property name="binDir" value="${projectDir}/MyBinaries" />
    <property name="resourcesDir" value="${projectDir}/resources" />