[Orgmode] org-cycle-agenda-files is not cycling through all my 15 agenda files - bug?

[Charles Cave]

I restructured my personal productivity system from 3 files to 15 files
all of which are in my agenda file list.

The problem is that when I  used the C-' (org-cycle-agenda-files)
org-mode only cycles through 4 of the files. Needless to say, this
is annoying and I have to go to the menu to call-up the file list
then choose file.

My org-mode is version 6.36c running on GNU Emeacs 23.1.1 on Windows XP.

Here is my file list from .emacs

 '(org-agenda-files (quote ("c:/Charles/GTD/taskdiary.org"
                            "c:/Charles/GTD/newgtd.org"                        
                                "c:/Charles/GTD/IR.org"
                            "c:/Charles/GTD/kyo.org"
                            "c:/Charles/GTD/chinglish.org"
                            "c:/Charles/GTD/chat_er_pres.org"
                            "c:/Charles/GTD/certiv.org"
                            "c:/Charles/GTD/cer_publicity.org"
                            "c:/Charles/GTD/storytelling.org"
                            "c:/Charles/GTD/reading.org"
                            "c:/Charles/GTD/drawing.org"
                            "c:/Charles/GTD/fitness.org"
                            "c:/Charles/GTD/storytelling.org"
                            "c:/Charles/GTD/birthday.org"
                            "c:/Charles/GTD/music.org"
                            )
                           )
                    )