Possibly related issue.
I have a Midisport 4x4 USB, and added a Korg Nanokontrol, also USB.
On installation of the Nano, the Midisport disappeared from the Midi port options in Sonar X1, even tho both units were 'working properly' in Device Manager.
For now, I unplugged the Nano and had to reinstall the Midisport drivers to make it visible in Sonar.
This is not a case of a one Midi device limit in Sonar, because the Profire 2626 Midi port is always visible in Sonar. It looks more like a one USB Midi device limit so far.