Parts of Programm didn't work after deployment

Hi,
I've got following strange problem. My working computer is part of a domain. Our development server with the source codes is also part of the same domain. I've got "Full Trust" to my code. One part of the program starts a DTS package and writes protocoll output files. If I compile this and run this on my working computer all is running well. Now I copy my output directory to a test pc which isn't part of the domain. It resist in a own workgroug (e.g. "TESTGROUP"). When I now start my program and try to run the DTS package nothing happens. The protocoll files are created put nothing is written into them. The most strange thing is that immediatly after creation of the a protocoll file the first entry should be written.
But when I copy my source code onto another computer which is not a part of a domain. The third pc is also in a different group than the test pc (e.g. "MYGROUP"). When I compile it there and copy the output on my test pc all is working well on my test pc. The DTS package is executed and the protocoll files are written.
I have no idea what's the cause of that behaivor.
Does anyone here knows something about that issue?
I'm thankfull for every hint.

Akademos

P.S. My programming language is C#
On all computers Win2K SP 4 and SQL Server 2k SP3a is running.