I think you hit on the heart of the matter. I lost a lot of weight following the Atkins recommendation to give up bread, potatoes, pasta, etc. But then the weight loss stopped, and reversed a little, when I began to indulge in Atkins candy bars and other processed "low 'net' carb" junk food. I've now resolved to treat that stuff like bread, potatoes, pasta, etc - and see if the weight loss recommences.
Yep, that's the ticket. Avoid all that crap and the weight will start falling off again. I am no expert but I have done a lot of my own research on this and have gone from 280 lbs to 202 lbs since last november. Only 17 lbs to my goal.
Moderation is the key. I know some long-time low carbers who swear by having exactly one of those low-carb candy bars a day -- it satisifies the sweet tooth, and the mild laxative effect counteracts any tendency toward constipation.
(That laxtive effect has done a pretty good negative reinforcement job on me, to make sure I don't over-do it with the low-carb candies...)