At the beginning of the DS, Roger and David hated each other's guts. Then they eventually grew closer....however I have noticed during throughout the show's run, Roger went on a lot of business trips.
[spoiler]I mean, he's gone for most of the Quentin/Beth haunting Collinwood story, absent all the way throughout the entire Gerard/Daphne as ghosts story. Even during the time he was married to Cassandra, he seemed to have been gone for 3 or 4 weeks there.[/spoiler]
Now I realized that Louis was doing other projects off DS during these periods, but I'm talking about the character of Roger here....he supposedly wanted to improve his relationship with David and be a better dad, yet he always seemed to be going away to somewhere and staying away from Collinwood for long lengths of time.