I noticed that when switching between guides (i.e. Leveling and Dungeon) the recent version does not recognize completed quests correctly and the user is forced to backtrack and retick the already completed quests. This was my scenario:

I was using the leveling guide for Borean Tundra 70+, when I reached the Coldara area, I switched my guide over to the Nexus Dungeon Leveling Guide and started doing the prereq for the quests, etc. Most of the quests in the Dugeon guide exists in the leveling guide. After I finished doing all the prereq of the Dugeon guide and queue'd for Nexus, I switched back to the Leveling guide to keep questing while waiting for queue. The leveling guide did not recognize which quests I had already finished and I was forced to backtrack and retick all the quests I had already done through the Dungeon Leveling guide. Resulting in a 10minute downtime. This is very inconvenient, can this be looked at?

I also noticed that this quest on the guide displays the incorrect item on the quest item button of the addon -- I had to dig through my bags for the proper item.
http://www.wowhead.com/quest=11969