failed to write trace from web service

[orencs]

Hi
I am using IIS6 on Windows Server 2003.
I am trying to write to the trace log via Web Service but fails.

System.Diagnostics.Trace.WriteLine("some message");

I am using DebugView to see the traces.
The Web Service is the hello world example with the statement above.

I have changed the username= attribute in the machine.config file to
"System". It does not help.
The ASPNET process is running under SYSTEM user.


When I am running the same code on other PC with IIS 5 and XP Pro it
works OK.
When I am running a simple Windows Form application with the same
statement everything is OK.


Hope that rings a bell for someone.

Thanks in advance

Oren