I posted a temp fix for these newer builds of WM6.5 that all have the ringer bug. Below is how 2 fix. If you have an alert sound that you need for text or an alarm just drop the wav file in my documents folder. (\storage card\my documents\whatever.wav) and it will let you pick it for an alert.
I built my own rom using the ppckitchen. The odd thing was I was having the same issues. All the stock ringtones and notifications would not work when trying to preview them under start > Settings > Personal > phone. I would get the file cannot be played it might be corrupted message, However All my ringtones that i made that were not wma or mp3. I make my ringtones in wav format bc they play faster and with less delay and always work. When selecting one of my own ringers they work fine. So a temp fix might be to convert the tones u want to a wav format.
I do not have the bug with the new mighty 5 rom. as it plays wma and mp3 ringers fine.
Something even more odd was the phone would play mp3's and wma files using any music player such as s2p, wmp, and mort player. The bug only affected the ringers and notifications.
After playing with MR5 i noticed i don't get the error that the ringtone is corrupted it just does not play when selected... But guess what my wave tones play fine... It may take a little more space but I have plenty as I always store my ringtones on my storage card. \\Storage Card\My Documents\My Ringtones\
And when restoring my contacts between flashes using Dot Freds PIM Backup 2.8.
Sense the ringers are always in the same place as soon as I restore the contacts all of the custom tones I have set for each caller work no need to re-set up anything. The only ringer I have to mess with after flashing is the default tone.
http://forum.ppcgeeks.com/showthread...474#post868474 Original thread