(Note: I found no section for bug reporting, so my appologies if this isn't the right place for it)
I encountered the following problem, less then 1 hour ago:
I had a quest (Trade - Glomdar Pick) listed I wanted to do, but I was unable to immediately execute it because I didn't have sufficient caravans available.
I had only 10 minutes left to accept the quest, so I accepted it. This gave me several hours to actually complete the quest, enough for me to get the caravans available and make the shipment.
However, a very short time after I accepted the quest (I assume after the original 10 minutes for accepting were over) I got a message that I failed the quest.
Now, as I see it, once I accepted the quest the original time limit for acceptance should no longer be relevant and only the timelimit for actually completing the quest should be considered. Hence, I consider this to be a bug.
Might be a good idea to have a look at fixing this.