I was trying to export a new video to YouTube via FCP X, but it wasn't working because an earlier video was stuck.
Any new video would sit in the export queue, called 'Share Monitor', and then cancel out after a while.
Clicking the 'X' beside the stuck file wouldn't work.
I went over to the Apple Support Discussion boards and found my answer.
You need to go to Macintosh HD > Username > Library > Application Support > Apple Qmaster > Storage > ' A folder with a bunch of Letters and Numbers> Jobs
Then delete the content in that folder.
In Lion, this directory is hidden.
To get here in Lion: Hold the Option key in the Finder and use the Go menu.
Thanks Tom Wolsky:
Reboot the computer and open up FCP X.
Go to Window > Background Tasks.
All exports are gone from the Share Monitor queue.
Note: I wen to a live class with Steve Martin and he's great at teaching Final Cut Pro X.