Somehow connected to other questions, but with a twist.
I have an app dual-signed with SHA1 and SHA256 certificate (Thawte), properly timestamped and all. Cert does not have enough reputation, so SmartScreen is warning about untrusted source, which is a correct behavior. What is not correct is, that on both my computers (both were used for development and signing the binaries), this warning displays "Unknown Publisher," but when I've asked a friend with completely unrelated computers to test download the app, publisher is correctly displayed in this warning.
Is there some SmartScreen cache or similar, that needs to time-out or is there something I am missing altogether?
It seems there was some caching involved, as the issue resolved itself in a few days.