Kolab installation process on a vserver doesn't work

[h3x0g3n]

Hi,

I'm currently trying to install Kolab Server 2.2.0 on my vserver. But it 
doesn't work and I don't know what to do. I have installed Kolab Server 
2.2.0 on another vserver before, but this one just doesn't like Kolab ;-)

My server runs Debian 4.0

Here is my kolab_install.log:
------------------------------
Changing to temporary working directory 
/tmp/install-kolab.31576.1754.23429.14413 ...

Kolab installation tag (TAG):       kolab
Kolab installation prefix (PREFIX): /kolab
Kolab version (KOLAB_VERSION):      2.2.0
Kolab user name (USER):             kolab
Kolab user base UID (KID):          19414
Kolab restricted UID (KID):         19415
Kolab non-priviledged UID (KID):    19416
Exclude following Kolab packages:  

Received no instructions. Trying to determine required action...
Found an OpenPKG environment. Assuming upgrade...
----------- SETUP COMPLETED -----------

 Now running:

   /kolab/bin/openpkg build -kKBuZ -r 
"/tmp/install-kolab.31576.1754.23429.14413" -p "ix86-debian4.0-kolab" -D 
openldap::with_pth=no -D sasl::with_ldap -D sasl::with_login -D 
sasl::with_ntlm -D postfix::with_sasl -D postfix::with_ssl -D 
postfix::with_ldap -D imapd::with_kolab_nocaps
            -Dkolabd::kolab_version=2.2.0
            -Dkolab-webadmin::kolab_version=2.2.0
          openpkg-tools openldap postfix kolabd kolab-filter 
kolab-freebusy kolab-webadmin fbview-kronolith horde-kolab-client | sh

---------------------------------------
/kolab/lib/openpkg/openpkg: command substitution: line 298: unexpected 
EOF while looking for matching `''
/kolab/lib/openpkg/openpkg: command substitution: line 300: syntax 
error: unexpected end of file
/kolab/lib/openpkg/openpkg: line 298: exec: shtool:path:Error:: not found
------------------------------

And this is line 298 from /kolab/lib/openpkg/openpkg:
------------------------------
eval "exec ${cmd_shell} ${cmd_path} \${1+\"\$@\"}"
------------------------------

I found out, that ${cmd_shell} is empty. Probably this is the mistake, 
but how can I solve it?

Thanks for your help in advance

Stephan