I am going CRAZY!!!!

I use the playtex drop ins and DD drinks with the fast flow nipples. The past week or so the nipples have been clogging and it is driving me nuts. I even bought new ones!!!

I dont get it...she doesnt get rice or cereal in her bottle at all and its like this "film' (saliva maybe?) clogs the nipple and DD SCREAMS bloody murder that she cant get anything out. This could happen 5 or 6 times throughout a feeding!

Thoughts?