Can't be 100% sure, because I didn't execute getbalance or listaddressgroupings just prior to upgrading my auto-denominating headless v0.10.12.17-beta, but it appears that v0.10.12.18-1-g7a4f01e-beta auto-denominated my balance again. Balance went down 0.001 DRK again, and listaddressgroupings...