Are you using a Korean font in your document? It also looks like you've only started the form in InDesign, but you've created the form in LiveCycle Designer, is that correct?
If you've used a Korean font, is it possible that the people who can open the file do have the Asian language pack installed?
Karl Heinz Kremer
PDF Acrobatics Without a Net
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http://www.khkonsulting.com