Amazon moving around my inventory. Going out of stock as a result. WTF AMAZON?!

I've got a few items that sell fairly well and I have to say I feel like I do a good job of making sure Amazon holds plenty of inventory on any given day and I try to make sure that we're especially well-stocked during this time of the year for obvious reasons.

Just when I think everything is great, 80% of my inventory goes into "reserved" status, where I assume Amazon is moving it to various warehouses for more efficient distribution. As a result, a couple of my items have gone out-of-stock while I wait for them to sort things out and scramble to prepare more inventory to send on short notice.

I know it's just one of those things but I wanted to vent and share my frustration with my fellow FBA'ers.