Hi Random Brunette,
Thanks for posting about your problem here. We do have measures in place that prevent sellers from purchasing shipping insurance on items for which checkout has not been completed, so I am quite confident that the root cause of this problem is that your buyers paid via money order instead of proceeding through the eBay Checkout system.
We are also aware of the problem that caused you to receive an error message indicating that items shipped to Afghanistan cannot be insured, instead of one indicating that insurance cannot be purchased since checkout is incomplete, and we will be addressing that with a future update to our site.
In any event, if you are still looking to insure this item through Auctiva, please contact our customer support team by mousing over the "Help" tab within your account and selecting the "File Support Case" option and we will be able to generate a policy for you from our end.
I hope this helps.