Seems to be a problem when questing in a party. The details on quests especially when the items required are looted, goes up and down like a yo-yo, for example, mirefin heads in Dustwallow, I had 11 and it would show 0, then 3, then 7, then 0 again, and when my fellow quester moved out of range it was still showing the quest but as 0 even though he had completed it, and would remove it from my list and then re-display it. Was getting very hard to see what was left to do on quests. Last time I was in a party was a couple of weeks ago and didn't have this problem then.

Will check this after holliday... need to buy another account to test this out :(

My wife and I live with this all the time, happy to test changes or debug if you need me to. I'm a software developer, but haven't worked in lua/wow, so not sure what the debugging process is.