Same issue here. I withdrew 0.39 BTC 4.5 hours ago. Still it says "No such transaction".

All you new people, will you PLEASE read through the forums ... use the search function. The answer to why this happens, how long it can take, issues going on right now, "No such transaction" are all there. They don't need to be answered over and over again. Just search before you post.
I even posted a "search" message yesterday and you guys didn't see that either which means no attempt to look at even recent posts to check for problems or answers.