I've only had my 8330 for six months, and in the last two or three weeks, the red LED will blink, even though I have no new messages, e-mails, missed calls, whatever. It's really obnoxious, and the only way I have thought to get rid of it is by turning the phone off (by holding down the "end call" button), and turning it back on.
i downloaded twitterberry to my 8330 and it was set to auto update timeline and the led would blink every time so if you have twitterberry that maybe something to check.
I have an 8320 and I only started experiencing this after I upgraded to OS V4.5.0.81 If I ignore a call or miss a call, my led will blink red untill I do a battery pull, soft reset or receive a message of some sort. Every now and then, it will also stop blinking when I make an outgoing call. I think that it is just a bug in the OS.
I have none of those apps all of you mention besides BBM & Weathereye I did install QuickPull and haven't seen any more unnecessary blinking *knock on wood*