I tried exporting NX sheet to .dwg file. I faced few conversion error in it.
1. If the dimension present in the sheet is cylindrical dimension it gets converted as BLOCK Reference in a .dwg file.
2. If dimension text is overwritten the overwritten text in .dwg file comes in a wrong manner.
3. The conversion works successfully only when the dimension is set as a vertical or a horizontal dimension.
Please let me know if you have any solution to it.
You should read the Caveats and Product Notes included with the NX Help Documentation.
There are some know limitations regarding dxf translations.