Gacutil Returns Access Denied

[Ram]

Hey,
I have a WebService running in IIS with an administrator account.
The WebService runs gacutil with Process.Start.
On one 2003 Server it works, but on the other, I get in the output
stream a response from gactuil says it failed - "Access Denied"...
If I set the Virtual Directory to run with Impersonation to an
Administrator account and just in case I set the ASPNET user as a local
administrator, what more do the gacutil need to succeed?
Thanks ahead

Ram