I'm pretty sure this has been mentioned before - I thought it was kind of fixed, but it's back..

After posting message in a game I can come back to it a few minutes later and all is fine, but after 20 or 30 minutes, I get a message alert on the game. Of course I go to check to see if someone responded, but it turns out the alert is for MY message.  It's happening pretty consistently.

Yep.  Happening for me too.

Here's two previous threads that brought this up.  In both cases, I don't think the fix was ever found.

http://www.wargear.net/forum/showthread/1994/Cant_clear_Private_Messages_icon_from_blinking

http://www.wargear.net/forum/showthread/2330/Notification

Are either of you using the Flash player, or only Native?  I've had a theory about this problem for a while that it has to do with what "mode" you're in when you write the message.  If memory serves, my experience previously was that the problem did NOT happen when using the game overview page (click on the name of the game from the games list, DON'T click on the arrows that start the flash or native player) to post messages.  But if you wrote an in-game message from inside the player (clicked on the arrow for the native player) then it did happen.   It's almost like the native player doesn't flag the message as read after having sent the message.

My memory was also that the Flash player didn't have this problem, which lead to me thinking that the flash player does some sort of reload that marks the message read flag on your games, so that the envelope icon doesn't show up 10 minutes later.

But I'm also too lazy to test this theory, and I never use the flash player anymore, so I can't be trusted.

I only use flash and occasionally get the envelope thingy message alert on my own message, though, not all the time.