Did you try it on just one NT server or multiple servers? Also, are you running it locally on the NT machine or remotely?...

According to Microsoft:
"The backup file CANNOT be written to a remote server because this function is implemented by a service running in the LocalSystem account, which does not have credentials on the remote machine. However it is possible to write the file to a remote machine using a null session."

The BackupEventlog function comes from the win32 api in the advapi32.dll. I found this info on MSDN. I'm not really sure if there is a good way to get around it.

Brian