BlackArmor NAS Network Storage Server

[BartmanLACA]

I have a BA4xx series NAS I populated with four 2 TB Seagate ST32000542AS Barracuda LP drives. I've been happy with the NAS with the exception of the incredibly slow transfer/copy rates of files accross my gigabit network. However I was just checking on the web interface of the NAS and found I have a "degraded" volume due to a failed #2 drive. I did some checking on the other settings and such and rebooted the NAS and now it shows as "good" however I am concerned about the potential failure of this drive again or for that matter other drives. They are covered under the warranty, however I am wondering if I did want to get a newer or different brand drive is I use the same speed/size drive would I be able to replace it in the array or do I have to use the exact same model drive to rebuild the array if #2 fails again? Looking over the materials and information provided by Seagate online and in the manual doesn't really indicate the correct configuration and method for replacing it. Any help would be greatly appreciated!!! 

Thanks in advance! 

[BartmanLACA]

OK, still HOPING to get a response here, I had Drive #2 fail again yesterday requiring a reboot to regain the drive functionality, of course it took nearly 2 days to "recover" the array, I have RMA'd the drive to Seagate since it is still under warranty. Now my question is, I am getting the drive via Advanced Replacement, meaning they're going to send me a new drive, and I have to send the bad drive back with in 10 days, so once I receive the replacement drive, if I don't have a "failure" of the drive what steps do I need to do to replace an apparently "good" drive???? I have been looking in the manual and instructions and can only find the steps covered when you're getting a degraded or missing drive. Is there any other methods? I really would appreciate any advice anyone can offer on this, I don't want to have to pay Seagate for such a question. Thanks folks!