1) Start an export from a forum post to Box.net
2) Change your mind when authenticating
3) Go back to the forum discussion
4) Observe the carnage (error message contains CONTROLS and also prevents forum display)
I think it should still show the forum discussion, and perhaps have a little alerting "!" icon or something next to the "Add to portfolio" link to show that it's in progress and some , clicking on it would go to a separate screen that tells you what is going on and lets you cancel/complete etc.