When Teal'c and Ronon are talking in the Mess, Teal'c's sleeve changes position between camera shots.
The location of Chuck the Technician changes between shots during the sparring scene.
One of the guards at the Midway station reacts to the Wraith coming from the Stargate before they pass the event horizon. The intergalactic gate bridge being supposedly secure, they have no reason to react before seeing that the travelers don't actually come from Atlantis.
When the Wraith dial Earth on the Midway station, on two occasions, the Pegasus version Stargate sound effects are used, not the original Milky Way version "steampunk" Stargate sound effects that you would expect.
Both Teal'c and Ronon are watching the DVD, but their eye-lines are different.