arcpy - Why does the method partCount in ArcGIS always give back a value of 1?

Does anyone knows why method "partCount" in arcgis version 10.0 always gives me back value 1, even when I have object with interniorring or multipart object?

partnum = 0
partcount = feat.partCount
while partnum < partcount:
    outFile.write(str(inRow.GetValue(inDesc.OIDFieldName)) + " " + str(partnum) + "\n")
    gp.AddMessage(str(inRow.GetValue(inDesc.OIDFieldName)) + " \\ " + str(partnum))

    part = feat.getpart(partnum)
    part.reset()
    pnt = part.next()
    pnt_count = 0
    while pnt:
        outLine = str(pnt_count) + " " + str(pnt.x) + " " + str(pnt.y) + " " + str(pnt.z) + " " + str(pnt.m) + "\n"
        outFile.write(outLine.replace(".", sepchar))
        pnt = part.next()
        pnt_count += 1
        if not pnt: # ?

            pnt = part.next()
            if pnt:
                outFile.write("InteriorRing\n")