please help... unwanted noise with xpand & structure ??

[lemieux]

i've searched the threads and cannot seem to find anything about this...

with pro tools hd 8, every time i load up any session that has a midi instrument Xpand or Structure and i record enable that track i get a CRAZY low end hum that sounds like some odd midi feedback loop. this started out of nowhere and i cannot, for the life of me, figure out what i've done wrong. i've trashed all of my prefs a million times and nothing. any ideas? (i'd be eternally grateful)

thanks!