Flaky 1st Gen Drobo Bottom Slot?

I have a 1st Gen Drobo that recently gave me a scare. Basically, I was close to a yellow light but with diligent file deletions I was able to manage without a problem. I was ready to buy a 2nd Gen anyhow so no biggie. I got the 2nd Gen Drobo and hooked it up with no problem full of 1TB WD Greens. I had disconnected the 1st Gen to totally eliminate the chance of something happening. After I re-connected it, guess what? Something happened. The bottom drive went to red, and things started to melt. I had not been able to copy anything to the 2nd Gen so I’m scrambling to copy data over to the 2nd Gen. Meanwhile the 1st Gen is performing like a PIG during the file copy jobs. Long story short, Drobo phone support made things worse before they go better. I still give them a glowing report however because if I had the right answer, they asked the right question. End of chaos…flashed the firmware with beta upgrade with no luck. Performed PIN reset and that did the trick. Unfortunately I had to swap my 4 new 1TB WD Greens to the 1st Gen during the process. The firmware upgrade made them unreadable by the un-flashed 2nd Gen. No biggie, I was just happy now to have them both online.

I got my data from 1 to the other and have a somewhat mirrored set of Drobos. Now comes the next problem. Last weekend I moved the whole system (iMac) to another room and when I fired up the 1st Gen Drobo, i have no activity on the bottom drive. No light no nothing. The top 3 drives are now flashing Green/Orange and this time only need 5 hours to rebuild. But what about the bottom drive? I have read some posts over the past few days that speak to my specific issue “Once after a move of my Drobo, it acted as if the last drive was not inside, so I popped it out and placed it back in, but the array had to rebuild.”. Is this an inherent problem with the bottom slot of 1st Gen models? Where is my “once healthy” bottom drive? Is this going to happen to me, I’ll pop it out, re-seat it and all will be fine except for an arduously long rebuild of the data? Should I be concerned with this flaky behaviour?