There are a few things to think about:
1) Yeah, cheap scale... check that.
2) Make sure you're also cutting out SUGARS as well. If ketosis is what you want, be careful of the sugars found in fruits and other natural starches. Still good for you, just limited quantities.
3) Start doing more than walking if you haven't already. I'm in a plateau phase right now as well (30lbs down, 20 more to go) and am going to be focusing a lot more on my "lift heavy things" and "run for your life" sessions.
Also, just don't get discouraged. Sometimes your body needs to heal a bunch of other systems inside itself before it gets to (or back to) weight loss. I know my first week SUCKED when I cut out sugar, and I had zero weight loss to show for it, but my skin cleared up in about three days. Sometimes you've just got other stuff to work out.
If you want to reach the end of the trail, first you must find the beginning.
If you want to be strong enough to walk the trail, trust your feet.
If you want to go fast, go alone - if you want to go far, go together.
6'0" white female, age 24
Pre-paleo: 247.8 lbs
Current weight: 212.8
Goal: 199.9 (and to rock a two piece bathing suit surfing in Costa Rica this November!)