Unfortunately, I had the same problem as post 1 as well. I powered down the TS-439 Pro (Raid 5 setup as well), removed the hard drives, etc., and still had the same message - I can assume that it may be what ordo described in an earlier post (power supply).
I only purchased the TS-439 PRO in September 2009 - so it's a little dissapointing that it's not even 1.5 years (young) that it has experienced a problem - it's been flawless up until now. Whatever the firmware was at the time of purchase (I may have downloaded an update just after purchase as i initially didn't have access (couldn't see) "surveillance station" on it) i didn't mess with as everything was working so well for me. I was a little nervous as I thought i should have the latest firmware on the 439 to be able to hot swap the disks into the newer 459 unit.
I had intended to purchase another NAS in the near future - which came a little sooner than expected... I purchased a TS-459 Pro, carefully placed the 4 disks (in the right order) in the new NAS, powered it on, and I was amazed that I did not seem to need to do anything - all of my settings were intact. I'm still touching wood as i type this. I'm no tecchie at all, and found the whole process extremely stressful just thinking about it.
Luckily for me, where i purchased the new NAS, the kind folks at i-store in Melb. helped me out with the process (carefully following the Qnap recommended system migration
procedure) - happy (and extremely relieved) to say it seemed to work out ok. I did not need to perform step 7. of the migration, ie, "start migration", as the new NAS recognised all of the drives/setup and all of my other settings and shares. Being a non-tech person, I must say - it certainly seemed to me to be "plug and play" - (instead of windoze "plug and pray")!
Although i'm not happy about my just over 1yo TS-439 Pro going to maintenance heaven so soon, I was VERY relieved to have the ability to basically "hot swap" my RAID5 (4x1TB) Seagates (seemingly) seamlessly into the new box - AND all of my shares, settings, on the NAS were maintained - and all of my PC windows shares were maintained, etc.
Hopefully this post may assist someone else in a similar position... I love my NAS. (And I'm still touching wood.)