Chain suck as i understand it, when i experienced it, is that the chain "snags" on the front chain ring, either ring, and pulls on the rear derallieur, causing noise and jumping of the derailleur. The chain snags on the bottom of the ring, however. not during shifting. it is a symptom of worn front chain rings. doesn't sound like thats what you have. Have not experienced the problem you descrive but if its already cost you one chain,, perhaps a trip to the lbs is in order?