Is it possible that the audio interface is plugged into a different USB port than the one it was in during the driver installation? Bob Bone This defaults to 32-bit, and I have never changed it, but did see a post where someone got your same error message when they had it set to 64-bits, and it went away when they changed it back to 32-bits. Just curious - what is your Render Bit Depth set to? (Edit>Preferences>File>Audio Data). I found some info on the Cakewalk web site that was referencing the Unable to Open Audio Device error message you posted this thread about. NOW, with regard to your reported issue: 1. Sorry for any confusion the above may have caused. So, again, the above has nothing to do with the error you posted - it was just something else I happened to see. A sample rate of either 44.1 k or 48 k, record bit-depth of 24 bits, and an ASIO Buffer Size of 128 should get you down to somewhere between 9.3 and 10.5 milliseconds, and that should eliminate that audible 'lag' or any dropouts or crackles.
You want to try to keep your total roundtrip latency down to around or just under 10 milliseconds.
I just happened to notice from your listed settings that your total roundtrip latency was up over 15 milliseconds, and latency that high produces an audible lag between playing a note and hearing it play back through Sonar while recording. It does not, and is a completely separate issue. I am sorry if I inferred that the observation I made about your ASIO Buffer Size had anything to do with your error.