You guys gotta remember, the time he actually TRAVELED with Jack, Jack wasn't Immortal.
When Rose/Bad Wolf Entity made Jack immortal, The Doctor promptly dumped him and ran off.
Jack showed back up when 10 and Martha went to Cardiff, and only stuck around until the end of the Harold Saxton story. He showed back up during the Children of Time story.
The Doctor and Jack really didn't "travel" together.
When Rose/Bad Wolf Entity made Jack immortal, The Doctor promptly dumped him and ran off.
Jack showed back up when 10 and Martha went to Cardiff, and only stuck around until the end of the Harold Saxton story. He showed back up during the Children of Time story.
The Doctor and Jack really didn't "travel" together.