I think you have to remap the UV for all models with different LODs.
The reason why you can't simply take the LOD0 UV and use it for the
LOD1 or LOD2 UV, is because there is typically one UV coordinate per
vertex.
So, the LOD0 model has too many UVs for your LOD1 or LOD2 models.
How would it know which UVs to use, and which UVs not to use?
It doesn't know.
The purpose of importing/exporting UVs is to transfer UVs to a model
that has the same number of vertices as the one that created the UVs.
Trying to import/export UVs to a model with a different number of
vertices will either fail, or mess up the UV map.
However, everything changes if you are modelling in a program like
3dsmax.

Since the model is inside max, you can reduce the poly count,
and still retain the UV info for each vertex. This is because both
the vertices and UV are being reduced at the same time, so no associations
are broken.
HTH
[This message has been edited by Lithium (edited 07-08-2001).]