Issue Burndown Chart incorrect after import issues from CSV

Steps to reproduce:

1. JIRA imports the issues from CSV and sets the status to closed.
2. There is no history on the issue showing a status change from Open to Resolved, or something similar
3. GreenHopper scans for status changes in the history, finds none and assume it's still Open, therefore does not mark it as Done
4. Re-opening an issue means GreenHopper sees that re-opening as a +1 to the number of issues that are not done (because it went from Done to Not Done)
5. Closing it again will then mean that GreenHopper simply does a -1 to burn down, but is only taking away the +1 it added on the re-opening

Workaround
Use Project Import functionality to import the project and issues to JIRA