Enemy Within (1996 TV movie):
-	Grace seems to think that the Doctor's blood is very strange when she looks at it under a microscope, but when we see the probe's view of it, it looks pretty normal.
-	Apparently it's impossible to make a "more accurate" atomic clock - there is no isotope with a decay rate as efficient as the caesium istope used in current atomic clocks. Besides, the most accurate chronometers are based on pulsars (or so I'm told).
-	When the Doctor tells Grace about his ability to regenerate, his voice says "I have thirteen lives" while his lips clearly say "twelve".
-	When the Doctor and Grace escape from the Institute by lowering themselves down on a fire hose, notice that there's nowhere near the length needed for the 20-feet-or-so drop that they make.
-	When the Doctor is strapped up in that Clockwork Orange-esque gear at the end, the insides of his lower eyelid are visible on long-range and medium shots, but not on some of the close-ups.