PPCGeeks - text sound disappears randomly

i've noticed this for a while, and haven't been able to come up with a solid answer. i have the audiofix (lite) installed, but even after uninstalling, and trying the full audio fix (that got rid of all my notification sounds pretty much). sometimes i notice that my phone only vibrates when i receive texts and emails, and if i restart it, everything works fine. i don't understand what the problem is. anyone else experience their notification sounds going mute for no apparent reason? they play fine when i go into the settings and hit play, but they don't work at all until i restart the phone.