Been a while since you've done a battery pull??? Battery Pull: Leave your device on, pull the battery, leave it out 20 seconds, put your battery back in, wait for your device to boot up.
If you want an easier fix than a battery pull or even QuickPull, get LedReset, it does simply what the title states, and no need for a battery pull! Sorry, I dont have the link handy, but you can find it here on CB if you do a quick search.
Strange, I have never had this happen to me on my 8900. It must be an app or something that you guys are using. Definitely do the battery pull, it is good for your device anyway.
if your using 5.0 on your phone i noticed that when you do profile edits and you use the option to test your ringtone the LED stays red.. til you do a batt pull