A bit more info for the file?
Where did U get it?
What size is it?
When was it modified?
etc...
Open this file with an ordinary text viewer like vi and read the file header (first few bytes or letters of the file). Post the header or/and the file here maybe someone can help you.
It's posible it isn't an Open Office document!
It culd be:
ODT Document; Microsoft Office 97 Binder;
ODT OOMF Data Table. Data from the Object Oriented Micromagnetic Framework.
ODT Open Document Text. A standard file format for word processing documents.