Hello
In the list of plugins on my site it was still saying Downloader Pro support expired, when I clicked the upgrade link it took me to your site, where I copied the license key and then pasted it into the plugin on my site, then it said it was registered and active again. I think the license key was the same it seemed to need me to update it anyway before it activated again properly.
So it looks like as you said the order was active but for some reason my installation did not pick it up until I forced it to update by refreshing the license key.