Just a FYI for anyone else having similar problems...
My new Razr Maxx HD kept losing the phone and text custom ringtones. I had them on the SD card as I have always done with my numerous previous Moto phones, but the HD didn't like them there. Every time I would plug the phone into my computer it would unmount the SD card and then lose the settings. As it turns out, all I had to do to fix the problem was to move the custom ringtones to the internal phone storage in the ringtone and notification folders and all seems to be fine now!
As a side note, I'm not really happy about not being able to access the internal phone storage through "mass storage" when connected to the computer. Not sure why they have changed this, as I used this functionality all the time on all the previous phones...

I am going to try this.

I am having this problem. I am going to try this and see if it works.

"but the HD didn't like them there."

LOL, this phones failures just keep stacking up. The phone didnt like them in memory? Oh! Because its EXTERNAL MEMORY, that makes SO much sense, and people are wondering why a lot of new phones coming out do not support external memory, its a pain, inconvenient, causes problems, etc. The only thing I DONT like about not having an SD card slot is they charge too much for the extra internal memory, but I guess if no problems, then its worth it?

*sigh...
It makes TOTAL sense Jimmy. Ringtones and Notifications SHOULD be on Internal Storage. SD Cards, since they can be removed, should not have any system settings on them at all.