abacab
This problem sounds very strange...
If I start Sonar with my controllers disconnected, I usually get a pop-up dialogue about 20-30 secs after I reconnect my controller:
"The above audio/MIDI device was connected to your system. Do you want Sonar to add this device now? Yes/No"
No Sonar restarts, no reboots, etc required. Plug and play!
I have several controllers and they all seem to function this way. Never had to reboot, but the most I ever had to do was restart the DAW or audio application after turning on a controller.
I wonder if you are doing something that prevents Sonar from showing this pop-up device found dialogue? Like is it popping up on a second monitor somewhere that you have defined that is not visible, or popping under a 32-bit plugin UI?
funny enough, if I power cycle my MIDI controller, I get this dialog box too! The MIDI port is selected on the track, but when I hit the keys, I get no incoming MIDI data.
Sonar is smart enough to detect the presence of the keyboard, but not smart enough to accept the data. This tells me it might be listening on the wrong port. I would suggest Cakewalk check into the code for what port to listen to. I have it on MIDI Omni by the way just as a side note.
The only remedy when this happens is to reboot, or close Sonar, open Device Manager, delete the MIDI controller and scan for hardware changes, then re-open Sonar.
And again, when this issue does occur in Cakewalk - i can open Reason or any other standalone synth and the MIDI controller works just fine. This is isolated to Sonar ONLY.