As a huge fan of the ACW (while acknowledging its shortcomings,-for instance its absolute refusal to recognize major 7th chords in some instances and displaying them as slash chords instead), I'm wondering if it's the program or, with all due respect, your workflow.
Is there a specific song you were having trouble with? I'd love to try and see if I can get better results by tweaking various parameters.
All the best,
DB