msmcleod
How about checking "Suspend Audio Engine When Cakewalk Is Not in Focus", open your project, then quickly go to another window whilst it's loading?
 
You could also try unchecking MMCSS before loading your project. In theory, this should give SONAR lower priority for resources, which may slow down the loading of resources allowing things to settle down whilst the project is loading.
 
Also try unchecking "Always Stream Audio Through FX".
 
You probably want to re-enable MMCSS & "Always Stream Audio Through FX" after the project has loaded tho.
 
I'm not sure if disabling the Multiprocessing Engine will help or make things worse, but its probably worth messing around with.