This morning I logged in to my MCC and one of my accounts had a dozen or so keywords gone dark.
I fired up AdWords Editor, and clicked on the "Get Recent Changes" and acknowledged those changes, but it listed all keywords for that ad group as being active.
Rinsed and repeated - same behavior.
So for some reason, the AdWords Editor is NOT always in sync with the AdWords console.
Sent off a report to support.