We have actually since resolved the issue with the tool that you mentioned, and ran it for your account a bit earlier today. As a result, hopefully none of the items on your Active Listings page are missing thumbnails any longer at this point in time.
I see that the support case you filed on this subject was updated with this information shortly after you posted this message, but I figured I would reply to you here as well for the potential benefit of others who may see this thread.
If you notice any remaining issues of this nature, please don’t hesitate to follow up with us through your open support case and we will be happy to continue working with you.
We apologize for any inconveniences this may have caused!