I have recently upgraded my DS411j and DS211j from 3.2-1944 to 3.2-1955. Then I decided to disable HDD hibernation and noticed strange behavior in Power settings panel, for example, "Fan speed mode" on "General Settings" tab is empty, "Beep Control" tab has two extra settings ("Beep when extension unit fan malfunctions" and "Beep when system resets"), "UPS" tab reports that UPS is not connected. This happens on both units.
If I select or deselect some checkboxes on "Beep Control" tab and confirm changes, it may go back to normal - extra checkboxes are removed from "Beep Control" panel and I can get Device Information for my UPS, but pressing "Previous Page", "Home" or [x] buttons has no effect (browser says "Error on page"). I had to refresh page in browser to get back into Control Panel, but when I enter Power settings, there are extra Beep checkboxes and Fan Speed is empty again.
DS411j was attached to APC 800BR UPS and DS211j was using DS411j as network UPS. I have disabled UPS in power settings and detached all USB devices (UPS and flash disk), but problem is still there.