Why does Authorization element need the computer name?

[Hani Atassi]

I am developing a secured Web Service that only specific Windows role can
access it. I have the following in the configuration file:

<authenticati on mode="Windows" />
<identity impersonate="tr ue" />

<authorizatio n>
<allow roles="WDInterf aceWebService" />
<deny users="*" />
</authorization>

I cannot access the Web Service even if I logged in with correct user. I
always get the ASP.NET Access Denied page. It only works if I provide my
computer name as the domain like the following:
<allow roles="COMPUTER NAME\WDInterfac eWebService" />

Why would I have to specify the computer name? I would assume it should
default to local computer if I didn't provide the domain name.

It's not feasable for me to put the ComputerName because the web service
would be installed in many computers with different names.