CX75 fw23 Addressbook not showing

[Mirsad]

I've been browsing the forum and it seems I can't find similar problem. So at first I had fw13 on my Siemens CX75 and after some time the addressbook is gone. I noticed the files are still there, but that the phone just won't show any contents. After some back and forth copying and flashing I partially restored it while previously backuping the original addressbook and appointment files.
I upgraded to fw23 then hoping that the same kind of problem will never happen again. But yesterday it happened again. This is what happend. The battery was at the end, and the phone went off, after an hour and a half I changed the battery pack and noticed that there was no phone book again. I was cheking the files for changes and then I realized that the phonebook stopped working when two files in folder -Data\System\Apo\idx- 00000 and 00010 (they seem to be the only files changing throughout the usage of the phone) reached the same size as before 00000 at 5064 bytes and 00010 at 12036 bytes.

Thank you for any given answers, solutions, etc.