I am trying to purchase an HR24 from an on line vendor. One of the vendors list it as HR24NCR and notes that it is replacing an HR24NC. Anyone know what the NCR means? The last HR24 100 I purchased was from Amazon for under $200. Now Amazon shows the HR24 Plus 400 available and it is $224. They do have just an HR24 listed for $198. I assume the Plus means it has a larger hard drive (400 instead of 100)?