I'm in the same boat as you. I started at 215 and did a straight low-carb for about 3 months until I hit the low 190's... switched to CKD (currently in my third week) and have been pinned at 190 since the first week (of CKD). The scale is literally pegged directly on 190. It won't budge! I appear to be getting leaner though... I'm going to get my bodyfat tested on Thursday to see what's up.
Not sure about suggestions, since we both have the same problem... maybe up your fat intake? drop your cals? drink more water? cut out artificial sweeteners? add AM cardio? be patient and stay the course?
How low are you trying to go? I'd like to get to ~180 and see how things look. The last 10 lbs are always the hardest...