Since SeriesGuide has already completely switched to TMDB for show data, it may not match with what is on Trakt. E.g. the season and number of an episode might be different. It will require Trakt to fix those shows to use TMDB data as well. You can report the affected shows to Trakt on their Trakt site (look in the left sidebar for a report button).
Background info: TMDb Migration Issues and Questions