Default [Q] ICS Ringtone reverts to default after unmount of internal "sd"

I have ICS 4.0.4 and the mp3 i have set as a ringtone is stored in /sdcard/Ringtones folder. /sdcard/ is the default internal memory that is shown as sdcard. My phone is lenovo A660. Whenever the phone is connected to the pc and i use the memory as an external card (thus unmounting it from my phone and mounting it to pc) the ringtone reverts back to default.

On a rooted phone a solution would be to save the ringtone in the internal memory (the one not partitioned as an external) but there must be another way (for non-rooted phones). I cant believe that ics is build on the idea that everytime you want to move files from your phone you have to reapply the ringtone settings.

I have searched some threads mentioning the same problem but i didnt find a non-root solution