This is not unusual, and it's avoidable. I don't know how much you're eating, but if you're eating what you listed to satiety, then it's not the quantities. Likely it's one of the things that everyone must go through in the stages of adapting to a fat burning mode. In most cases, getting more salt is a simple answer:

http://forum.lowcarber.org/showthre...210#post8626210

You've lost a good amount of weight, but note that much of this weight is due to your body flushing water and salt. You no longer retain sodium the way you did when you were eating carbs. Review the Salt Thread and try some of the suggestions.