Created attachment 112346 [details]
Example of described problem in 3 steps; output in .PDF for fast comparision

LibreOffice does handles Header Tables in unpredictable way in specific conditions
Test bed: LibreOffice 4.3.5.2 under Win7 – Word 2007 SP3
          Libreoffice 4.2.7.2 under xUbuntu Linux

Description:
Table defined with header-rows longer than a page in two variants:
- Header N rows long on a table with M rows
- Header spans the full table

Problem: 
as soon as the contents of Header-rows make them not fit in the bottom-free page space, the table begin is pushed on a new page;
as soon as the contents of Header-rows make them not fit in the page space, part of the header and the following table-rows disappear under page-bottom. 
In the example below a 20-rows table with 10-rows header was defined, contents of first 10 rows was made higher of bottom-free page space.

As a comparision, text was saved in docx format and opened with Word 2007 SP3. This program react different: as soon as the header-rows does not fit anymore in the bottom-free page space, the header definition is preserved but neglected, and presentation is done as the table has been defined with 0-rows header.

Even more: if .odt version is opened with Word 2007, program complains “
The file <file-name> cannot be openend because there are problems with the contents. The file is corrupted and cannot be opened”, propose to recover it, if OK is pressed contens as from .DOCX is shown up.

Three steps are presented: 
1 has no header table defined
2 has 10-rows header table defined, but made such that header fits in the 1st page free space
3 has 10-rows header table defined, but made such that header dose not fit in a page space