You just added a few ringtones of your own to your android device, but after each reboot you lose them and they are set to something else, or muted altogether? Just like something was resetting them, or they were not saved correctly?

Well, most probably it’s because you copied the MP3’s on your SDcard, under

• /ringtones
• /alarms
• /notifications

or even under

• /media/audio/ringtones
• /media/audio/alarms
• /media/audio/notifications

(they all work as they should).

After a reboot, it may happen that for some reason your sd card takes too long to be mounted/scanned, hence Android cannot actually find anything in the specified folders, because they aven’t become available yet.

I wouldn’t know if there are any solutions to make Android mount your SD any faster, but a pretty workaround consists in copying those files directly in the internal memory. Ugly workaround if you ask me, since you’re taking away precious space for applications, still…

So, just take your desired MP3’s, and drop them in the internal memory (using a root file explorer, like ES file explorer), respectively in

• /system/media/audio/ringtones
• /system/media/audio/alarms
• /system/media/audio/notifications

this way they will be treated just like builtin ringtones (you will actually notice the system ringtones in those folders, which you can delete since they are useless anyway, to save some space), and will be available right after boot.