lock ups on when moving data

[BC]

I am running FC2. I have Samba configured to share out a 30gb RAID 1 partition. 30gb on the main drive and a separate 30gb drive make up the RAID1 (md0) when I move files from the windows machine (like an entire directory 12gb) the entire FC machine locks up after 5 minutes with no error messages. Then I have to hard reboot the machine. any ideas -- is it the RAID or samba or a problem with I/O ?

 BC