Audio inputs suddenly misssing in Cubase 7.5

Tonight I fired up my DAW to do some recording and I got a message when loading my current Cubase 7.5 project that the MR816 audio in 3 was unmapped. I clicked through the error and when I got into my project I discovered that audio in 3 was missing from the list of devices! I tried restarting Cubase, restarting the system with no success. I then hooked up an instrument to audio in 3 without using Cubase and went into the MR Editor and input 3 was physically working just fine. For some reason Cubase will now not list it as an input device. Does anyone have any suggestions as to what I should try to resolve this problem? Thanks.

Well it seems to be resolved now. I started up Sonar X3 on the same system and Sonar did see the missing input. Then I rebooted the system and fired up Cubase and input 3 was showing up in the device list. I’m not at all sure why it is working now - maybe something to do with Sonar enumerating the audio inputs?