How far are your discs and pads gone? Mine started doing exactly as you described about a week before I changed them all round and they were pretty much gone. Since the change all has been well.
Apologies but just a small
I'm interested in hearing more about the bushings as I have noticed mine starting to grab at camber changes and undulations but figure my geo may have gone out since changing the wheels. Something I'll be sorting once I get a new suspension setup.