Cannot edit an Excel worksheet from scheduled task

[teognost]

I am trying to edit an Excel worksheet using the sample provided here:
http://kinook.com/Forum/showthread.p...el.Application
with small changes (attached is the bld and excel file).
When trying to run this bld file -both tom VBP and from a scheduled task -all works ok from my machine (WinXP X86,VBP 8.0 X86,MS Office 2007).
When I try it from another build machine -W2k8 R2 X64,VBP 8.0 X64,MS Office 2010 -it works ok from VBP environment,the log says:

7/5/2012 6:44:36 PM: Building project step 'mod worksheet'...
xlApp object is NOT empty!
xlBook object is NOT empty!
xlSheet object is NOT empty!
Cell 1,1 has value:1000
7/5/2012 6:44:36 PM: Build successfully completed (elapsed = 00:00:00).

But when running this build from a scheduled task -never works.
Log says:
7/5/2012 6:44:06 PM: Building project step 'mod worksheet'...
xlApp object is NOT empty!
xlBook object is empty!!!
xlSheet object is empty!!!
7/5/2012 6:44:06 PM: Build successfully completed (elapsed = 00:00:00).

So I would like to ask you what could be the problem causing this bld project not to work from a scheduled task (basically for some reason xlBook and xlSheet are empty objects )...