i think that people get frustrated sometimes because they confuse a lot of the initial weight loss as being fat when in is fact it is half or more from dehydration of your body. water is very heavy. thats why you lose weight fast in two weeks and then it slows. it creates a wrong picture and wrong expectations. atkins also does not address this in any way to my knowledge or even talk about it.
when you deplete glycogen stores (stored sugar) in your muscle, you also dehydrate your muscles and your body since water is stored in conjunction with that sugar. i think the number is something like 4:1. meaning that for every gram of glycogen in your muscles, your body stores 4 grams of water. so fairly significant dehydration can occur in the first few weeks.
thats why you also will most likely be constipated because your body attempts to scavenge water from your bowels.
if you are interested more in the physiology of how the diet works... read this book "the ketogenic diet" by Lyle McDonald. if you are interested in a short explanation of the physiology behind it read here
http://low-carb.org/lylemcd/cyclic1.htm (but not that this is a different variation of the diet which is explained)
most likely, if you hit a plateau or stopped losing weight, it is because your body is starting to react to the diet and the sudden drop in body fat and is trying to adapt or because you ate too much carbs one day. remember that fat is also very heavy and takes a long time to process. you could just have a bunch of poo inside you also
the most common reason for me to stop losing weight if/when i do this, is that i start drinking too much diet pepsi. i think the citric acid (is an artificial sweetner) causes it and i am very sure that caffein does not as Atkins suggests. if i stop drinking everything and start drinking only water for a couple days, its fine again.
eating a lot of fat is important as well for your body to burn fat in this manner. you should not be eating "fat free" anything because that defeats the very process at work. having a very low ratio of fat to protein could be why your body would react as well and try to protect fat stores.
you should not get impatient or frustrated... just be consistent and exercise and everything will be ok.
you are doing the right thing about trying to get information. dont listen to people. talking about nutrition is often no more useful than debating abortion or global politics with most people. i would recommend that you just try to read as much as you can from as many sources you can and make your own decisions about what works and what doesn't for you.