Slow Writing to W2K Cluster server …..

I have a Windows 2000 Cluster servers where when I write a large file to it, it copies the files at 100% of network utilization and suddenly drop off to 0% and pauses the copy process. In few seconds, it continues with the copy process. I was using Perfmon on the server to view the state. When I perform the same copy to any other W2K servers that are not in a cluster, not an issue. If anyone has seen a similar problem and resolved that issue, PLEASE let me know.