If you are using the same credentials there isn't a reason for this. I'd open up a service request so we can take a look at your log files and see what type of access you received to that target.
Thanks for your response.
With regards to the log files, can you give a pointer so that I may investigate this
Well what I would do is search for the word "credential" in the log file. You will be able to determine if the authentication was successful when you locate that section. There is more to it though than successful authentication. For instance someone with just user level access can authenticate but they would not have the file system or registry access that is needed. Once you locate the credential successful message if you have the proper access to the file system and registry you will not receive any more messages on the topic. If you don't have access though you will see a message.