Slow network speeds

The slow speeds started a few days ago when I was writign a large number of files to the NAS.  At the same time, the NAS started spamming me with informtion free emails about every hour.

I have a 3 TB MyBook Live

It is connected to a gigabit switch and my HP desktop has a gigbit NIC.

Some backgound.  I was bulk converting my music form Apple lossless to mp3 to make streaming to my iPhone more efficeint over low bandwidth connections.  I did part of my collection with a direct write to the NAS before realising I needed to use differnt settings.  So I erased the files and started a new batch the next day.  Then the coding software ran very slow.  I changed again and wrote to a USB drive and am now using MS Synctoy to transfer the files to the NAS.

The sync has been running for four days and has moved only a small portion of the files.  Directory reads to the NAS in windows explorer are also very slow.  It can take a from 30 seconds to a minitue to open a new directory.  Downloads to my iPhone and Android tablet seem to be unaffected.  

Any ideas on how I can speed this up and stop being spammmed by my own device?

 ETA  The Twonky web interface works very quickly and selected songs start playing right away. It is the WD interface that is slow.  

Everthing is OK now.  As is the way sometims when you ask a quesiton the answer occurs to you.  I reassigend drive letters in Windows 7 and everthing is working a good speed again.  Thanks to the WD community for being there to let me think outloud!