Exactly the same problem resolved in issue:
http://www.openoffice.org/issues/show_bug.cgi?id=22670  is happenning in version
1.1.2 when using "MS Word 97" filter.

I've tried it on Linux using python UNO.  PDF export works fine using "Hidden"
Property to open, but "MS Word 97" Filter crashes OpenOffice.   Without "Hidden"
property it works fine, but I can see how document is opened and converted.  I
really would prefer do this in batch mode and without GUI activity.

Here you have the piece of code:

import getopt,sys
import uno
from unohelper import Base,systemPathToFileUrl, absolutize
from os import getcwd

from com.sun.star.beans import PropertyValue
from com.sun.star.beans.PropertyState import DIRECT_VALUE
from com.sun.star.uno import Exception as UnoException
from com.sun.star.io import IOException,XInputStream, XOutputStream

class OutputStream( Base, XOutputStream ):
    def __init__( self ):
        self.closed = 0

    def closeOutput(self):
        self.closed = 1

    def writeBytes( self, seq ):
        sys.stdout.write( seq.value )

    def flush( self ):
        pass


def main():
    retVal = 0
    doc = None

    try:
        opts, args = getopt.getopt(sys.argv[1:], "hc:",["help",
"connection-string=" , "html", "htmltopdf", "pdf", "doc"])
        format = None
        url = "uno:socket,host=localhost,port=2002;urp;StarOffice.ComponentContext"
        filterName = "Text (Encoded)"
        for o, a in opts:
            if o in ("-h", "--help"):
                usage()
                sys.exit()
            if o in ("-c", "--connection-string" ):
                url = "uno:" + a + ";urp;StarOffice.ComponentContext"
            if o == "--html":
                filterName = "HTML (StarWriter)"
            if o == "--htmltopdf":
                filterName = "writer_web_pdf_export"
            if o == "--pdf":
                filterName = "writer_pdf_export"
            if o == "--doc":
                filterName = "MS Word 97"


        #print filterName
        if not len( args ):
            usage()
            sys.exit()

        ctxLocal = uno.getComponentContext()
        smgrLocal = ctxLocal.ServiceManager

        resolver =
smgrLocal.createInstanceWithContext("com.sun.star.bridge.UnoUrlResolver", ctxLocal)
        ctx = resolver.resolve(url)
        smgr = ctx.ServiceManager

        desktop = smgr.createInstanceWithContext("com.sun.star.frame.Desktop", ctx)

        cwd = systemPathToFileUrl(getcwd())
        outProps = (PropertyValue( "FilterName" , 0, filterName , 0 ), \
                    PropertyValue( "Overwrite" , 0, True , 0 ), \
                    PropertyValue( "OutputStream",0, OutputStream(),0) \
                   )

        inProps = PropertyValue( "Hidden" , 0 , True, 0 ),

        # ## Workarround ##
        # if filterName == "MS Word 97":
        #    # Don't act in hidden Mode to generate DOC, due to a bug in OO
        #    inProps = ()

        for path in args:
            try:
                fileUrl = uno.absolutize( cwd, systemPathToFileUrl(path) )
                doc = desktop.loadComponentFromURL( fileUrl , "_blank", 0, inProps)

                if not doc:
                    raise UnoException( "Couldn't open stream for unknown
reason", None )

                if filterName == "Text (Encoded)":
                    doc.storeToURL('%s.txt' % fileUrl,outProps)

                if filterName == "HTML (StarWriter)":
                    doc.storeToURL('%s.html' % fileUrl,outProps)

                if filterName == "writer_pdf_export":
                    doc.storeToURL('%s.pdf' % fileUrl,outProps)

                if filterName == "writer_web_pdf_export":
                    doc.storeToURL('%s.pdf' % fileUrl,outProps)

                if filterName == "MS Word 97":
                    doc.storeAsURL('%s.doc' % fileUrl,outProps)

            except IOException, e:
                sys.stderr.write( "Error during conversion: " + e.Message + "\n" )
                retVal = 1
            except UnoException, e:
                sys.stderr.write( "Error ("+repr(e.__class__)+") during
conversion:" + e.Message + "\n" )
                retVal = 1
            if doc:
                doc.dispose()

    except UnoException, e:
        sys.stderr.write( "Error ("+repr(e.__class__)+") :" + e.Message + "\n" )
        retVal = 1
    except getopt.GetoptError,e:
        sys.stderr.write( str(e) + "\n" )
        usage()
        retVal = 1

    sys.exit(retVal)