--- src/java/org/apache/poi/hssf/model/InternalWorkbook.java	(revision 1357535)
+++ src/java/org/apache/poi/hssf/model/InternalWorkbook.java	(working copy)
@@ -624,9 +624,16 @@ 
      */
 
     public void setSheetOrder(String sheetname, int pos ) {
-    int sheetNumber = getSheetIndex(sheetname);
-    //remove the sheet that needs to be reordered and place it in the spot we want
-    boundsheets.add(pos, boundsheets.remove(sheetNumber));
+        int sheetNumber = getSheetIndex(sheetname);
+        //remove the sheet that needs to be reordered and place it in the spot we want
+        boundsheets.add(pos, boundsheets.remove(sheetNumber));
+        //reorder records list as well
+        int baseIndx = records.getBspos() - (boundsheets.size() - 1);
+        int recIndx = baseIndx + sheetNumber;
+        int recNewIndx = baseIndx + pos;
+        Record rec = records.get(recIndx);
+        records.remove(recIndx);
+        records.add(recNewIndx, rec);
     }
 
     /**
--- src/testcases/org/apache/poi/hssf/usermodel/TestBugs.java	(revision 1357535)
+++ src/testcases/org/apache/poi/hssf/usermodel/TestBugs.java	(working copy)
@@ -2238,4 +2238,26 @@ 
         // make sure we are still readable
         writeOutAndReadBack(workbook);
     }
+    
+    /**
+     * Test case for bug #50083.
+     * If bug is present, test case throws an IllegalArgumentException
+     * on workbook serialization.
+     */
+    public void test50083() {
+        HSSFWorkbook workbook = new HSSFWorkbook();
+        Sheet sheet0 = workbook.createSheet("Sheet_00");
+		
+        Sheet sheet1 = workbook.createSheet("Sheet_1");
+		
+        //Breaks propper sheet order here.
+        workbook.setSheetOrder(sheet1.getSheetName(), 0);
+		
+        //Deletes wrong sheet record due to the wrong reordering above.
+        workbook.removeSheetAt(0);
+		
+        //Exception gets thrown here because of incorrect data is supplied 
+        //when calculating output buffer size on workbook serialization.
+        writeOutAndReadBack(workbook);
+    }
 }