i love my 320, but seems when i try to copy multiple files to a media shared drive, the network speed varies.  The speed goes to ~10MB, then goes down to 0.  Then goes back to a high speed, then to 0.  This fluctuation continues until all the files a done copying.  I have tested this same process with the same pc connected to another one of my NAS devices and i don't have the same problem.  
is there something that can be done to eliminate this issue?
thanks