Baloo reindex all files after a reboot

I have this question,
I have set baloo to index the folder i want, including the content of the files.
I started with about 30000 files, but every time I reboot the computer, it starts all over again, tells me the numer of files to index is 30000 and the total number of files is 60000
the question is, is this the normal way baloo works? or is it something wrong with my installation

Thanks in advance for your attention.