Working off paragraphs in two successive While loops

Dear experts,
In continuation of "How to define the offset for a textrange (after a TAB)?" i have implemented the snippet into the existing script-flow (simplefied for the presentation here):

• Read an RTF which contains two parts of tabbed paragraphs. See the file FM-biblio-collected-test.fm.
  This contains 4 paragraphs in the first part and 3 paragraphs in the second part.
• Reading pgfs in the first part works perfectly. These all start with [[   (script lines 10 ... 26)
• The first pgf of the second part (paragraph number 5) is already read, terminating the first While loop due to missing [[ at the beginning.
• Further processing of this paragraph (script lines 27 ... 35) reveals that not paragraph 5, but paragraph 1 is processed! (textrange in line 41 is from position 21 to 22, which fits only to the first paragraph!
• Of course this leads to the message in line 43

Why does line 29 not get the same paragraph object (paragraph 5) as it was handled correctly in the previous While as last object?

// Have the expanded RTF file (FM-biblio-collected-test.fm) open 

#target framemaker  
  
var goRtfDoc = app.ActiveDoc;  
var pgf = goRtfDoc.MainFlowInDoc.FirstTextFrameInFlow.FirstPgf;  // get first pgf in flow
var TAB = String.fromCharCode(8);               // FM has wrong ASCI for TAB
var tabRange

// --- read the temp/formatted citations --- "formatted" consist of the reference number only
  while (pgf.ObjectValid()) {
    pgfText = GetText (pgf, goRtfDoc);
    if (pgfText.substring (0,2) === "[[") {       // citation lines start with [[
      parts = pgfText.split(TAB);                 // get the two parts of the line
      parts[0] = parts[0].replace("[[", "{");     // replace [[...]] by {...} for find in user doc
      parts[0] = parts[0].replace("]]", "}");
      if (parts[1].substring (0,1) === "{") {     // this placeholder is unresolved, skip it
        nUnres += 1;
        pgf = pgf.NextPgfInFlow;
        continue;
      }
//    gasFmtCitsRaw.push (parts[0]);              // store the placeholder citation
//    gasFmtCitsFmt.push (parts[1]);              // store the formatted citation (just a number)
      pgf = pgf.NextPgfInFlow;
    } else { break }                              // first line of bibliography encountered
  }
// --- read the bibliography paragraphs
  while (pgf.ObjectValid()) {                     // until end of doc
    tabRange = GetTabRange (pgf, goRtfDoc);       // Get the text range starting after the TAB to the end of the paragraph.  
//  gaoBibliography.push(tabRange);               // store the paragraph-part in the array
    goRtfDoc.TextSelection = tabRange;      // for later use in tests
    goRtfDoc.Copy (0);                      // Check manually what can be copied
    alert ("are we OK?");
    pgf = pgf.NextPgfInFlow;
  }

function GetTabRange (pgf, doc) {  
  var textLoc, textRange, findParams, tabRange;  
  textLoc = new TextLoc (pgf, 0);                 // Make a text location at the beginning of the paragraph. 
  findParams = GetFindParams ("\x08");            // Get the find parameters for finding a tab.  
  textRange = doc.Find (textLoc, findParams);     // Search for the string.  
  if (textRange.beg.obj.ObjectValid ()) {         // See if the tab was found.  
    alert (textRange.beg.obj.Unique + "    " + pgf.Unique);   //?? Is <> if cursor is not at start of pgf. 
    if (textRange.beg.obj.Unique === pgf.Unique) {// Make sure the tab is in the correct paragraph. 
      // Select the text from after the tab up to the end of the paragraph.  
      tabRange = new TextRange (new TextLoc (pgf, textRange.beg.offset+1), new TextLoc (pgf, Constants.FV_OBJ_END_OFFSET - 1));  
      return tabRange;                            // Return the text range. 
    }  
  }  
  return 0;                                       // TAB Not found
}  
  
function GetFindParams (string) {  
  var findParams = AllocatePropVals (1);  
  findParams[0].propIdent.num = Constants.FS_FindText;  
  findParams[0].propVal.valType = Constants.FT_String;  
  findParams[0].propVal.sval = string;  
  return findParams;  
} // --- end of GetFindParams
  
function GetText (textObj, doc) {
  var j, text = "", textItems;
  if (textObj.constructor.name !== "TextRange") { // Get a list of the strings in the text object or text range
    var textItems = textObj.GetText(Constants.FTI_String);
  } else {
    textItems = doc.GetTextForRange(textObj, Constants.FTI_String);
  }
  for (var j = 0; j < textItems.len; j += 1) {    // Concatenate the strings
    text += (textItems.sdata);
  }
  return text;                                    // Return the text
} // --- end GetText

Any ideas are welcome

Klaus Daube