New ShareSpace (in RAID 10) sometimes seems to hang during copying

My new ShareSpace seems to hang sometimes when I am copying files to it.  I cannot figure out why it is occurring, since I’ve eliminated as many variables as possible but the problem persists.

BACKGROUND: I just got a ShareSpace with two 1TB drives.  After updating the firmware, I filled the remaining slots with an additional 2 1TB drives and set the drive to RAID 10.  See image below for drive models.  All are Caviar Green, and I kept the jumpers on the two drives that I added.

I’m now in the process of moving files off other external drives to the ShareSpace.  The files are coming from WD externals hooked up via Firewire 800 to a Mac.  The Mac is connected to an Airport Express that is connected to the ShareSpace.

During certain parts of the day, I can quickly copy GBs worth of files to the ShareSpace.  At other times, a much smaller amount of date, say 200 or 300 MBs, will take three or four times as long or just get stuck part of the way through.  Often, the problem will present itself as getting about half way through the copying process and seem to hang, but after several minutes (sometimes many, many minutes) it will suddenly continue the copying process.  I’d blame it on others querying the ShareSpace at the same time, only they are not.

If anyone has a suggestion, I’d greatly appreciate it.  Right now, I am a bit nervous concerning the safety of the data I am putting on the ShareSpace.

Thanks in advance.

-FilesFilesFiles

P.S. Twonkey, Mionet and iTunes Server are all off.

UPDATE: Direct uploads over Ethernet are, to be kind, glacially slow.  I’ve cancelled more than a few attempts after waiting over 45 minutes with an upload being stuck at one point.