And I would assume any other Debuff proc, but I haven't checked.
If you have the Dark Watcher's Despair set slotted in a toggle power, and have that power toggled as on, it applies the -25% recharge to you.
It's not a major issue or anything, just thought you might like to know for the next update.
Hm... I'll check this later.
I have noticed this too; I slotted it in Darkest Night on my tanker and it does the same thing