A number of Community Transit service changes went into effect last Sunday, March, 20th, with many updates concerning Mountlake Terrace. Details about the changes can be found at the Community Transit news page.
Unfortunately, the latest schedule and route data from Community Transit wasn't quite ready for the service change and the CT schedules in OneBusAway are likely to have inaccuracies in the meantime. I've been given access to half of the data I need, but I'm waiting on a GIS data dump hopefully later this week to complete the update. In the meantime, you unfortunately need to check CT schedule data in OneBusAway against official data sources at http://www.commtrans.org/ to ensure 100% accuracy.