Created attachment 60666 [details]
Original Excel-created Spreadsheet with Frozen Top Row

Simple spreadsheet created with Excel -- has top row frozen.  The pane XML from sheet1.xml is:

  <pane ySplit="1" topLeftCell="A2" activePane="bottomLeft" state="frozen"/>

Opened with LibreOffice 3.5.2.2, freeze is there.  Did no edits, just Save As with new filename, closed, and reopened with LO, freeze is gone.  Pane XML from LO-saved sheet1.xml is:

  <pane activePane="bottomLeft" topLeftCell="A2" xSplit="0" ySplit="1"/>

Frozen attribute is gone.

To replicate with attachment (frozen.xlsx):

1 - Open with LO; verify top row is frozen.
2 - Save As to new filename.
3 - Close LO.
4 - Open new file with LO.

--> top row no longer frozen