Hi Jean
A bug fix for the GETPIVOTDATA function has been released and tested for 4.1.5. This bug is the subject of a CAUTION table, the very last item, in this chapter. As this is, or will be, a 4.1 release it may be an idea to republish the chapter. I have altered the text in the CAUTION table to "Using the GETPIVOTDATA function with the second syntax variation in releases prior to LO 4.1.5, will return a #REF error.".
I reported this as bug 71234 which got marked as a duplicate of 69518.
I have put the altered chapter in ODFAuthors here http://www.odfauthors.org/libreoffice/english/calc-guide/draft-lo4.1/chapter-8-pivottables/view
should you wish to make use of it.
Regards
JohnS