I was trying to swap Windhelm's carriage for a new model, and got this:

http://galeon.com/yagare/tpf/error.jpg

It says the reference in the cell is pointing to a different base... which is exactly what should happen, considering I just duplicated the vanilla carriage static, pointed it to the new mesh, and ctrl+f′d the reference in the exact same place the original was. Every ref linking was kept, and the carriages work as they should. So, why the error?

What type of form is CartFurnStatic_Covered, furniture evidently? I'd wager the problem is that the replacement has no parent cell (according to the error report). Take a pic in TES5Edit and post a pic?