BodyBugg/BodyMedia calculations with MFP

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I started using a BodyBugg about 2 weeks ago. I have it synced with my MFP account. I usually do my meal planning first thing in the morning and plan my day around what MFP has my calorie intake at. I add a few extra hundred cals because I know that BodyMedia suggest I eat closer to 2000 cals based on my days and MFP has me at about 1680. Somehow when I go back at the end of the day or the next morning, I am always still several hundred calories under my food goal for the day. Is this going to effect my weight loss? Am I eating enough? I am a little worried about the calculatios from both and which one I should follow. Any sugestions or advice from what others have done?