ASPNET_SETREG runs on XP, not 2000

[microsoft.public.dotnet.framework.aspnet.webcontro]

I have a webservice up and running locally on my dev machine (XP) using
impersonate like so:

Line 5: <identity impersonate="true"
Line 6:
userName="registry:HKLM\SOFTWARE\Security\identity\ASPNET_SETREG,userName"
Line 7:
password="registry:HKLM\SOFTWARE\Security\identity\ASPNET_SETREG,password"/>

The webservice comes up fine on there, but when I moved it to a server
running 2000, I get this error :
Parser Error Message: Error reading the password from the registry.

I have read several articles, and tried many things, including granting
EVERYONE read access as a test, and I still get this error. What am I doing
wrong here?

I ran ASPNET_SETREG.exe on the server, saw the registry entry, granted
ASPNET read access (later giving it to EVERYONE), but nothing seems to work.

Thanks in advance for any help.