How many notes are you exporting here? It could well still be going depending on the amount of data you are exporting.
If there is nobody else accessing the database you could check the activity levels of Act and SQL in the task manager to see if there is any CPU activity happening. If there doesn't appear to be anything happening, then it may have hung and you could try killing the process and restarting the export.
For big exports, we've prevously seen them take longer than 6 hours.
