[Protein-crystallography] resolution range for refinement

[hothot c]

Dear all:
  I'm refining a protein structure complexed with an inhibitor. I found 
that if I refine the structure in the range from 20 to 2.37 angstrom, I can 
see a strong positive density in fo-fc map in the second binding 
site,However,if I choose to refine it in 10-2.37 range, this peak is nearly 
invisible.
  What's going on here?Which one should I trust, the more complete one?
Thanks