Virtual Desktop Extensions for Linux - install problems

Can anyone help me diagnose a problem installing/configuring vWorkspace for Linux desktop provision?

We have vWorkspace 7.6 installed on a test server, running Server 2008R2.  We're using web access to connect from clients.

Windows 7 targets are working OK.

My target Linux machine runs Centos 6.3 x86_64, it's in the same DNS domain.  I've installed xrdp and x11rdp, and tested using rdesktop from my client.  I've installed the VDE tools v7.6 and started the daemon.

In the vWorkspace console, I can add and initialise my target machine, it reports logon state "logged off".  When I connect from a client, I get a working desktop session and the logon state changes to "Pending".  The logon state stays on "Pending" for a while then reverts to "Logged off", and at some point the connector window closes.  The system log on the target machine shows broker messages are being sent, and the following lines when I start the connection:

Sep 13 17:47:40 dwggs001 qdcsvc: [broker_services.cpp:(311)/qdc_broker_prelogon_change_state_WTSConnected]  State has just been changed to WTSConnected.

Sep 13 17:48:42 dwggs001 qdcsvc: [broker_services.cpp:(343)/qdc_broker_prelogon_error_state_to_orig] preLogon error: State has just been changed to original(5).

Presumably it's not picking up my successful logon to the target machine - how to proceed from here?

Cheers,

Geoff Short

IT Services

University of York