The "Klingon sneeze" only appeared once, in the first season, I believe. Was it "The Neutral Zone," where some cryogenically-suspended humans are found and actually help in a confrontation with the Romulans?
George
I think it's the Next Generation episode "The Defector." A Romulan general believes that the Empire is building a war outpost in the Neutral Zone and thinks that out-and-out war with the Federation is a bad idea. The Enterprise heads off to the Neutral Zone, only to find out that the general had been fed misinformation.
George