ReadyNas Pro frequenty becomes unresponsive

My ReadyNAS Pro becomes unresponsive periodically (perhaps as frequently as once a week), which is not good for a NAS device. When this happens I can not connect to the device via RAIDar or the FrontPanel, and the device does not respond to pressing the primary button on the front of the device. The only thing I can do is press and hold down the primary button on the front of the device until it shuts down. Then, I have to either switch off the device or unplug the device, wait a few seconds, and then turn back on the device in order for it to boot properly. So far, the device has always booted backup, so long as I have removed all power to the device before rebooting, but I fear that it is only a matter of time before there is a disk corruption and I am screwed--this is my primary backup drive.

Has anyone else experienced this problem? Can someone inform me on what procedures I can go through to determine why the device is becoming unresponsive, and/or how to fix the problem?

Thank you!