flurry of old email notifies after repo migration to 2.0

We've seen this both times we've used repotools to export our 1.0 repository and import into a new 2.0 installation. Using the scrum template.

Many previously sent work item change email notifications are re-sent upon first server bringup (at least) after the import. I can't determine a pattern yet - whether its a repeat of the last week's emails, the current sprint, the last sprint or just some random smattering of old email notifications.

As an example, I did the export/import this morning (Aug 5) and received 2 notifications for comments added to work items on July 31. Others have received more, some with July 31 and some July 29 change dates.

Is this intentional/explainable? Is there a pattern? Will it stop?

Thanks!