Actually that data can be preserved fairly easily. Find the NK2 file, then
rename it to match your new profile. Delete the empty NK2 file created by
the new profile and replace it with the one you just renamed. All your data
will be back.
There is also a utility to provide more advanced editing and transfer of NK2
data: http://www.dcs-imaging.com/products.htm
All may not be lost. You may be able to recover data. Can you write to me
at www.dcs-imaging.com and possibly send your NK2 file to us? We might be
able to rescue that data for you. No promises, but we can try.