annoying forms authentication problem

[stucker79]

I am attempting to implement the code in this Microsoft example:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnnetsec/html/SecNetHT02.asp

This code is for authenticating against Active Directory.

The code works fine on my web server, but not on any other pc in the network. The error that appears is "Error obtaining group names. An operations error occurred."

Any ideas? I'm not finding too much on google! Thanks!