Just to add, from some of your comments and screen shots etc., other possible things (and or what Ive done in past).
- Win 8.1 (?) possible issues
- ? What Version of Sonar are you using? (from your first screen shot) I dont see plugin load balancing available?, (albeit I dont use it, as it causes me issues).
- possibly disable your sound blaster card if not already, when using Audio Interface (although I dont see it listed/activated in Audio/Devices anyway)
- while it may not be related to these issues, turn dithering to "none" (from your first screen shot), you probably dont want to accidentally dither bounced tracks, until your final export, where you can select it.
- in Preferences/Audio/Sync and caching, file system, Ive raised Playback/Record buffers from 128 to 512, not sure it helps but dont notice any negative effects.
- in Preference/MIDI/Playback and recording, under, "record" - Ive raise "number of buffers" from 64 to 128, and under "Playback" raised "Prepare using" from 500 to 1000, msec buffers, also while maybe not related to your issues here, Ive unchecked "always echo current midi track" (which is just my personal preference, I select echo on track when I need it.)
- while Im not 100% sure of these tweaks, most of these changes seemed to help with my old computer, and Ive just left like this with new computer, as I dont notice any negative effects, (perhaps slight start delay when pressing play).
Cheers