Kansas (2) - S4-E12
Visible crew/equipment: After Scorpius tells Braca that the future of Peacekeeper survival depends on him, it cuts back to Earth and when the Sheriff says, "I got the warrant. Let's go search that house," as the car pulls away we can see a nice reflection of a crew member and the reflector screen.
Continuity mistake: When John and his father are talking about the alien tech, while John's eating popcorn his father's holding a mug and points, but next shot he's still pointing and now the mug's suddenly on the table.
Bad Timing - S4-E22
Continuity mistake: When John's at Serenity Base, in the shots from inside the pod when Aeryn looks out the window John's standing beside the flag and their long shadows are cast behind them as he looks toward Earth, but when John's on the phone with Jack, in the overhead shots the shadows are being cast in front of him.
Chosen answer: It's never explained. John mentions a theory that his less technologically developed craft simply interferes with the wormhole less than the "superior" Vipers, but they never make a concrete determination on that point. But we also have to take into account the fact that Moya traverses wormholes with no ill effect as well.
Garlonuss ★